Ingredients:
- 2.5 cups All purpose flour
- 1.5 tsp Baking powder
- 0.5 tsp Baking soda
- 1 tsp Fine sea salt
- 0.75 cup Unsalted butter, softened
- 1.5 cups Granulated sugar
- 0.5 cup Light brown sugar, packed
- 3 Large eggs, room temperature
- 2 tsp Vanilla bean paste
- 1 cup Buttermilk, room temperature
- 2 tbsp Instant espresso powder
- 0.25 cup Boiling water
- 1 cup Granulated sugar (for caramel)
- 6 tbsp Salted butter, cubed
- 0.5 cup Heavy cream, room temperature
- 1 tsp Flaky sea salt
- 1.5 cups Unsalted butter (for buttercream), softened
- 4 cups Powdered sugar, sifted
- 2 tbsp Strong brewed coffee, chilled
- 1 tsp Cocoa powder
Instructions:
- Prep the coffee. Dissolve 2 tbsp espresso powder into 0.25 cup boiling water.
- Cream the fats. Beat 0.75 cup softened butter with 1.5 cups granulated sugar and 0.5 cup brown sugar until pale and airy.
- Add the eggs. Incorporate 3 eggs one at a time, followed by 2 tsp vanilla paste.
- Whisk dry ingredients. Sift 2.5 cups flour, 1.5 tsp baking powder, 0.5 tsp baking soda, and 1 tsp salt in a separate bowl.
- Alternate liquids. Add the flour mixture and 1 cup buttermilk in three parts, starting and ending with flour.
- Fold in coffee. Gently stir in the cooled espresso liquid until no streaks remain.
- Bake the sponges. Divide into pans and bake 35 minutes until a toothpick comes out clean.
- Cook the caramel. Melt 1 cup sugar in a pan until amber, then whisk in 6 tbsp salted butter and 0.5 cup heavy cream until velvety and smooth.
- Whip the frosting. Beat 1.5 cups butter with 4 cups powdered sugar, 2 tbsp chilled coffee, and 1 tsp cocoa powder until fluffy and cloud like.
- Assemble. Layer the cake with caramel in the center and frost the outside.