Step 1

Begin by preheating oven to 350 degrees then liberally spray 3 (9-inch) round pans with non-stick baking spray.

Step 2

In your mixer bowl, add eggs and both sugars and beat on high speed for 2-3 minutes.

Step 3

While mixture beats, combine cocoa powder, instant coffee powder and salt in hot water. Add liquid to eggs and sugar.

Step 4

Next slow down mixer to low speed and add flour, baking soda, and baking powder then add vegetable oil, buttermilk and vanilla extract to the mixer and beat until just combined. Batter will be somewhat thin but this is normal.

Step 5

Evenly pour cake batter into all three pans and bake for 22-25 minutes or until a toothpick inserted in the center comes out moist but mostly clean.

Step 6

Allow to rest for 10 minutes before removing from pans and cooling on a wire rack.

Step 7

Clean your stand mixer bowl and whisk attachment. Add the confectioners' sugar and butter and mix on low speed, increasing the speed to medium-high once the sugar is fully incorporated. Continue to mix until light and fluffy.

Step 8

Add the blackberry puree, vanilla extract, and salt and beat until the mixture is puree is fully incorporated.

Step 9

Once cake layers have cooled completely, frost cake with buttercream.

Step 10

Garnish with blackberries and edible flowers and serve.