Preheat your oven to 350°F (175°C) and prepare a 9-inch round cake pan by greasing it with butter and dusting it with cocoa powder.

Mix the dry ingredients—flour, cocoa powder, baking powder, and salt—in a large bowl until well combined.

Cream together the butter and sugar in another bowl until light and fluffy, about 3-4 minutes.

Add the eggs one at a time to the butter mixture, mixing well after each addition.

Pour in the bourbon and vanilla extract, then blend everything until fully combined.

Combine the dry ingredients with the wet mixture gradually, stirring gently until just mixed.

Bake in your preheated oven for 30-35 minutes or until a toothpick comes out clean from the center.

Cool the cake in the pan for 10 minutes before transferring it to a wire rack.

In a mixing bowl, combine softened butter, cocoa powder, and powdered sugar, then gradually add heavy cream until smooth.

Spread the frosting evenly over the cooled cake.