Rich and Fudgy Chocolate Cake with Mint Buttercream

INGREDIENTS

1 cup

unsweetened cocoa powder

2 tsp

instant espresso powder

1 cup

boiling water

1/2 cup

sour cream

2 tsp

vanilla extract

1 cup

unsalted butter, softened but still cool

1 3/4 cups

granulated sugar

large eggs, at room temperature

1 1/4 cups

all-purpose flour, plus more for dusting the pans

3/4 tsp

baking soda

1/2 tsp

salt

1 1/2 cups

unsalted butter, at room temperature

3 cups

powdered sugar

2 tbsp

milk

1/2 tsp

vanilla extract

salt

1 tsp

mint extract

drops green food coloring

chocolate shavings