I’ve been feeling a little down this week; saddened by summer weather coming to an abrupt end. It’s been cold and my body is going through it, sensitive to the sudden change. I’ve felt a bit sick, too, but I still was excited to get creative in the kitchen. I wanted to make something with lemon – it’s one of my favorite flavors but I really haven’t made many lemon desserts lately. I decided to temper the acidity of the fresh lemon with my garden basil. I’m thrilled with how this lemon basil cake turned out!

Lemon Basil Cake

The week started quiet and cold. The weather has suddenly shifted to mostly gray with chilly mornings. Initially I was excited to take some hoodies and sweaters out of my closet after a while. But since Monday I’ve come down with a cold. My body, and mind, are tired. But still, I like to keep myself busy. To bake and cook. So I endeavored to make a delicious, light, and summery recipe to wake myself up a bit. With a zing of bright lemon.

I headed to the grocery store on Wednesday morning after waking up far too early. I wore a face mask, spooked by my sudden sore throat and ugly cough. And I traversed the ghost-like aisles of the once bustling store early in the morning. The selection was good. So I grabbed a handful of tennis ball-sized lemons with bright yellow skins. I also picked up butter and eggs to have on hand. I went through self checkout and felt like a zombie, quickly overcome by my exhaustion and quickening cold symptoms.

Resting + Baking

The rest of the day I tried to rest. And I had some tea to fight off the cold. I thought about adding a slice of lemon. But I opted for an orange spice blend, which was delicious. I started to feel better. So I grabbed my camera, my black backdrop, and brought out the ingredients for my lemon basil cake. Luckily I had the foresight to leave the butter on the counter to soften before baking. I took my time and did some planning and research. I noticed a cake on Instagram that was uniquely beautiful. A square slab of chocolate layers with frosting and dried flowers on top.

It gave me an idea. Make a fluffy, light lemon cake and sandwich the layers with bright lemon curd. Then I could make a vat of basil buttercream with basil from my garden and pipe it on top. I would garnish my lemon basil cake with a lemon slice and fresh basil for color. So I started with the lemon cake. I made an easy, traditional cake batter, starting with creaming the softened butter with sugar. But first, I massaged a plentiful amount of lemon zest into the sugar to infuse the lemon essence into the cake. The mixer hummed away.

Lemon Cake Batter

Next I added eggs, vanilla, sour cream, and buttermilk. Most of the cakes I’ve made with sour cream and buttermilk come out extra moist and tender. Oil helps, too. My favorite banana bread starts by whipping the eggs with sugar into a thick, glossy, aerated mixture. So I slowly incorporated the liquid ingredients into my fluffy, creamy lemon butter. And a bit of lemon juice for flavor. Soon I had a pale, fluffy mixture that smelled strongly of lemon zest. All I had to do was measure my dry ingredients and fold them in.

I measured my cup-fulls of flour into the sieve over my mixing bowl. I added baking soda, baking powder, salt, and sifted the mixture into my silver bowl. Then I turned my mixer speed onto low and carefully dusted the mixture into the side, some of it catching on the mixer. So I brushed it all in and watched it incorporate, in two batches. It’s a pale yellow, semi-stiff and buttery batter that makes an amazing, tender lemon cake. I thought about adding fresh basil into the cake base, too, but I wanted to keep the flavor profiles in separate components.

Lemon Curd + Whisking

I struggled for a little bit to find the right baking pan. Overthinking. I wanted to split the batter into three cake pans and bake them. Then just trim the tops a little and have three thick layers. But I realized quickly that I only own two square cake pans of the same size. I thought about all my options, and finally decided to use a sheet pan. Mostly so the cake would cook quickly. I could cut the right shapes with a knife. So I spread out the batter on parchment paper, baked the cake until it was springy and golden, and removed it from the pan to cool.

It would make an amazing Swiss roll if you didn’t feel like cutting it up and stacking it. But I had a clear vision in mind for my lemon basil cake, and I let it cool as I moved onto the lemon curd. I started with some research, because I don’t make lemon curd often. Most recipes use a double boiler to slowly cook the custard. But I felt confident in just using a saucepan if I stayed on top of it. I whisked my mixture constantly – eggs, lemon zest, lemon juice, cornstarch, and sugar. A little salt. It bubbled and steamed and finally thickened into a pudding-like texture.

Slicing Lemon Cake Layers

In order to make sure I could whip it up into a thick frosting, I added some gelatin. It reminded me of the pastry cream I made for my sweet corn layer cake last year. I tasted my lemon curd when it was all mixed and delighted in the sharp citrus flavor. And I added in my chopped up butter, which melted and coalesced into a beautiful sauce. Into the fridge it went, in a clean and cold pan to speed up the process. I checked on it occasionally and made sure it wasn’t thickening too much. I covered it with plastic wrap.

Then I sliced my cake layers. I knew I wanted to have equal, thick rectangle slices that could be displayed with the layers exposed. So I needed to cut my long rectangular lemon cake into three equal smaller rectangles. In order to make it more grand and tall, I cut them all in half again to have six layers, and I stored them in plastic wrap to keep them from sticking. My lemon curd was chilling and thickening. So I rested and let chemistry do its job. I made burgers for dinner and my cold symptoms set in again when I went to bed.

Assembling my Lemon Basil Cake

After another rough night of sleep and coughing, I crawled out of bed to get some water. I moseyed around, then decided to go to the farmers market. For some reason this week my happy place became stressful and overwhelming. There were more people than usual. Tourists fighting for parking spaces. Strangers waiting in long lines for bread and croissants. I waited in a couple lines myself and looked at the basil. $5 a bag. Instead of indulging in the beautiful, sunny morning, I left and hurried home. I was in one of those moods where I just couldn’t deal with people.

So I spent the rest of the morning finishing my recipe. I checked on my lemon curd, which was super thick and creamy. I knew it just needed a quick whip with a whisk to get it nice and fluffy. My lemon cake was even more moist after being wrapped overnight, gently trapping the warm steam. I whipped my lemon curd and assembled my cake. Stacking 6 layers of cake on top of each other with generous, equal layers of sharp lemon curd. My cake log wobbled a little, so I crumb coated it and placed it in the fridge for a while to firm up.

Basil Swiss Buttercream

I moved on to my basil buttercream. Which I had been thinking about for a while. How to best infuse basil into a buttercream? What type of buttercream? Ultimately I thought back to one of my favorite recipes. By my favorite Masterchef contestant. A basil parfait, which is essentially a set custard with egg whites and sugar. Billie’s recipe uses a very smart technique, blending fresh basil with sugar to infuse basil into the core of the frosting. Mine whipped up into a beautiful green sugar. Which I then whisked with egg whites and a little salt.

I tried my best to avoid the double boiler on day one. But my Swiss meringue buttercream demanded it. After whisking for a while over the steam, you whip it up in the stand mixer into a meringue. I did just that, and marveled at the pale green basil meringue getting thick and glossy in no time. Quickly I prepared my butter, which I also considered infusing with basil. But the basil sugar was plentiful with herb flavor and green color. I turned the mixer down to medium and incorporated the butter nervously, hoping the frosting wouldn’t split.

Decorating My Lemon Basil Cake

It didn’t. So when I finished, I turned the speed up to high and made sure the frosting was sufficiently thick and creamy. I transferred it into a piping bag and placed it in the fridge to firm up a little. Other than that, I was done. All I had to do was slice my cake and frost it. I took the large brick out of the fridge and had fun slicing beautiful rectangles of two-toned yellow lemon basil cake and placing them on a baking sheet. Pretending I was preparing a tray for a window at my bakery. I put them in the fridge to firm again when I had lunch. Then, I finished plating.

I piped a large dollop of basil buttercream onto each cake slice. Which were each about 1-2” thick, by the way. With 6 layers of tender lemon cake and lemon curd. I pushed my spoon to indent the frosting a little, like I tried to do with my ice cream last week, and loved how it looked. Finally I placed a basil leaf and a small lemon slice on each. It looked beautiful. Just how I pictured it. So I felt relieved and excited to accomplish my vision after last week’s trials and tribulations. I took plenty of beautiful photos and froze half of the pieces for another day.

Lemon + Basil Taste Test

I put together a plate for myself to taste with the leftover cake scraps, along with extra basil buttercream. The slices I had were so beautiful that I didn’t want to touch them. I tasted everything along the way. Tender, lemony cake with a spongy, light texture. Sharp lemon curd with a thick, buttery texture. And a subtle, pale green basil buttercream. Sweet, floral, and perfect to cut the sharpness of the curd. All together it tasted heavenly. Perfectly balanced. Lemon basil cake with a perfect combination of citrus and herbs in a sharp, sweet cake.

I’m so happy with how this came out. I’ve been really intimidated by cakes lately, for some reason, so this pumped me up a bit. I’m dreaming of more cake slices like this, with the layers exposed. Chocolate and coffee. Walnut and apple. Blueberry and lemon. Maybe I’ll make a ginger version this fall. Next time I’ll invest in another square cake pan to make my life easier. Or I’ll make a Swiss roll to save some time. For now, I’ll be digging into this lemon basil cake all weekend. We’re going to a new Italian restaurant that looks amazing. Hopefully I’ll get some inspiration for my next recipe.

Thank you for reading! If you enjoy my recipes and art, be sure to check out my prints and Etsy page for 100’s of recipe cards and art prints. Use code THEFORKEDRING for 25% off.

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Lemon Basil Cake

A light lemon sponge with lemon curd layers and a basil buttercream on top

Course Dessert

Cuisine American

Keyword basil, cake, lemon cake, lemon recipes

Prep Time 4 hours hours

Cook Time 20 minutes minutes

Servings 8

Author theforkedring

Ingredients

• 4 sticks + 6 tbsp unsalted butter
• 2 1/4 cups + 2 tbsp white sugar
• Zest of 4 lemons
• 7 eggs + 4 egg whites
• 1/2 cup sour cream
• 3/4 cup light cream
• 1 1/3 cups lemon juice (4 lemons)
• 1 1/4 cups AP flour
• 3/4 tsp baking powder
• 3/4 tsp baking soda
• 1 3/4 tsp kosher salt
• 1/2 tsp sea salt
• 1 tbsp cornstarch
• 2 sheets silver gelatin
• 1 cup fresh basil
• Basil + lemon for garnish

Instructions

• Preheat oven to 350°F.
• In a medium bowl, measure 3/4 cup + 2 tbsp white granulated sugar. Add zest of 1 lemon and massage zest into sugar thoroughly.
• Cream 12 tbsp unsalted butter, softened, in a stand mixer on medium speed with the lemon-infused sugar.
• Add 2 eggs, one at a time, while mixing on low-medium speed.
• Once fluffy, add your 1/2 cup sour cream, 3/4 cup light cream, and 1/3 cup lemon juice. Turn mixer off once combined.
• In a large bowl, sift together 1 1/4 cups AP flour, 3/4 tsp baking powder, 3/4 tsp baking soda, and 1 1/4 tsp kosher salt.
• Add your sifted dry ingredients to the wet ingredients gradually, in 2-3 batches, folding with a spatula until no streaks remain.
• Line a large sheet pan with parchment paper and spray lightly with cooking spray. Spread your cake batter evenly on the full sheet tray.
• Bake for 20-25 minutes until cake is lightly golden brown and springs back when touched. Carefully remove cake on parchment from pan and let cool.
• To make curd, combine 5 eggs, 3/4 cup white granulated sugar, the zest of 3 lemons, 1 tbsp cornstarch, 1/2 tsp kosher salt, and 1 cup of lemon juice in a large saucepan.
• Cook over medium heat, stirring constantly with a whisk, until the curd is thick and pudding-like, about 5-10 minutes.
• Remove curd from heat and add gelatin (pre-bloomed in cold water), and 12 tbsp unsalted butter, chopped into small pieces. Whisk until smooth and combined.
• Transfer curd to a heatproof bowl and cover with plastic wrap, adhering directly to the surface of the curd. Chill for at least 2-3 hours.
• Once cake is rested but still slightly warm, wrap in plastic wrap if you’re not using until the next day. You can chill the curd overnight and make the frosting anytime.
• To make the frosting, blend 3/4 cup white granulated sugar with 1 cup fresh basil in a blender or food processor.
• Combine basil sugar with 4 egg whites in the (clean) bowl of a stand mixer. Place over a double-boiler on medium-high heat and whisk constantly to dissolve sugar, for about 5 minutes.
• Transfer stand mixer bowl to stand mixer and mix with the whisk attachment on high for 5 minutes until a meringue with stiff peaks forms.
• Turn mixer speed down to medium-low and gradually add 14 tbsp unsalted butter, softened, incorporating each piece fully into the meringue.
• Transfer your fluffy meringue frosting into a piping bag and place in the fridge until ready to use.
• Cut your sheet cake into 3 long rectangles, measuring the width of the cake with a ruler to ensure evenness. Then, cut each of the 3 long rectangles in half to make shorter rectangles.
• Remove lemon curd from fridge and whip with a whisk or in the stand mixer until fluffy.
• Spread a large dollop of curd onto the first piece of cake and spread evenly. Place another cake piece on top and repeat 5 times until the cake is assembled, ending with your last cake piece.
• Use remaining curd to spread a crumb coat around the exterior of the cake. Place in fridge for at least 30 minutes to 1 hour to firm up.
• Slice cake into 8 equal pieces (about 1.5″ thick) and place each on a baking sheet with the layers exposed. Pipe a large dollop of basil frosting onto each slice and garnish with basil leaves and lemon slices.

Notes

• The cake can wobble a bit when assembled because it’s so thin, but if you have trouble keeping it stable, assemble it in a cake pan.
• If your frosting is too warm, the butter won’t incorporate properly and it could split, or be runny. If this happens, place in the fridge for 30 minutes and re-whip. 
• Your basil sugar and egg whites are ready to whip when the grains of sugar have fully dissolved. You can feel it with your fingers.