The day before making your buns, combine whole milk and coffee beans. Cover and leave to steep in the fridge overnight.

The morning of making your buns, cook 3 sticks of butter with 1/2 cup coffee beans over medium until golden brown. At this point you can strain the beans and brown bits out or you can blend the mixture (once chilled) to infuse more coffee flavor.

Let brown butter cool and come to a soft but slightly firm butter texture before making your buns.

When beginning the coffee dough, turn on your oven light.

Heat coffee milk until warm, not hot. Add yeast and sugar to coffee milk. Leave to bloom for 5-10 minutes.

In a stand mixer with the dough hook attachment, combine flour, salt, and 3 tbsp white sugar. Mix on low to combine.

To the yeast and milk mixture, add your eggs, vanilla, coffee, 1/3 of your reserved coffee brown butter, and coffee extract.

With the mixture on low, carefully add your wet ingredients. Mix until combined.

When a dough forms, turn up mixer to medium and knead for 5-10 minutes until dough is cohesive and elastic. The dough should spring back when pressed but leave a small indentation.

Transfer dough to a greased bowl and cover with plastic wrap. Proof in the oven for 1 1/2 hours - 2 hours until the dough rises about 50%.

While your dough is proofing, make your coffee sugar (skip this step if you don’t have a high powered blender of food processor and substitute the 1/3 cup coffee sugar in the filling with another 1/3 cup of brown sugar + 1 tbsp instant coffee.

To make coffee sugar, steep 1 cup of coffee beans in 2 cups of nearly boiling water for 15-30 minutes until water turns brown. Add a few tbsp of water if your water has reduced drastically.

With the heat on medium-high, add 1 1/2 cups white sugar and stir to combine. Cook over medium-high while bubbling for 10 minutes or until the mixture thickens and darkens slightly. You can test if your caramel is ready (and will set like glass) by dipping in a spoon and smearing a test of the liquid on a silicon mat. If it comes off easily after a few minutes and breaks, it’s ready.

When your caramel is ready, pour the coffee bean and caramel mixture onto a large silicone mat to set for a minimum of 30 minutes.

When coffee brittle is ready, break into shards and in batches, blend in a high-powered blender or food processor. The mixture will be a grainy brown sugar. Strain any remaining hard coffee bits out with a fine mesh sifter.

To make the filling, combine 1/2 of your remaining soft coffee brown butter in a bowl with brown sugar, white sugar, cinnamon, salt, and 1/3 cup coffee sugar. If using instant coffee instead of homemade coffee sugar, combine butter with 1/2 cup white sugar, 1/2 cup brown sugar, 1 tbsp instant coffee, a pinch of salt, and cinnamon.

When dough is ready, remove from bowl and roll out into a large rectangle on a floured work surface (about 16 x 24”).

Spread coffee butter filing over the entire bun dough, leaving the edges bare. Roll the short side of the dough into a spiral log. Cut 8 - 10 buns from the dough with a serrated knife.

Place buns in a greased baking dish (they should be close together but not touching) and cover with a damp tea towel. Leave on the counter for 2 hours until proofed.

Preheat oven to 350°F 15 minutes before buns are done proofing. Remove tea towel from buns and check to make sure they’ve puffed until nearly touching. If they haven’t, place in a warmer spot for 30 minutes before baking.

Bake buns for 25 - 30 minutes until golden brown. Baking times will vary, so be careful not to overcook the buns. If they begin to brown too early, cover them with aluminum foil.

Remove buns from oven and let chill. While they chill, make your espresso frosting. To make coffee powdered sugar, place 1 cup coffee sugar in a blender with 1 tbsp corn starch. Blend until powdery and smooth. Repeat with another batch of coffee sugar and cornstarch.

Sift coffee powdered sugar to remove clumps or coffee bean bits.

In a medium bowl, combine your last portion of coffee brown butter with 1 1/2 - 2 cups powdered sugar or coffee powdered sugar. It should mix into a pretty thick frosting. Add coffee extract, a pinch of salt, and cooled espresso as needed to achieve a thick but spreadable cake frosting.

When buns have mostly cooled, slather with your coffee frosting and serve!