For the Cake:
Ingredients:

1 ¾ cups all-purpose flour
1 ½ cups granulated sugar
¾ cup unsweetened cocoa powder (preferably dark or black cocoa)
1 ½ tsp baking soda
1 tsp baking powder
1 tsp salt
2 large eggs
1 cup buttermilk
½ cup vegetable oil
2 tsp vanilla extract
1 cup boiling water
Instructions:

Preheat the Oven:
Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
Mix Dry Ingredients:
In a large mixing bowl, sift together the all-purpose flour, granulated sugar, cocoa powder, baking soda, baking powder, and salt.
Combine Wet Ingredients:
In another bowl, whisk together the eggs, buttermilk, vegetable oil, and vanilla extract until well combined.
Combine Mixtures:
Add the wet ingredients to the dry ingredients and mix until just combined. The batter will be thick.
Add Boiling Water:
Carefully stir in the boiling water. The batter will be thin, but this is normal.
Bake:
Divide the batter evenly between the prepared cake pans. Bake in the preheated oven for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
Cool:
Allow the cakes to cool in the pans for about 10 minutes, then remove from the pans and transfer to a wire rack to cool completely.
For the Frosting:
Ingredients:

1 cup unsalted butter, softened
3 cups powdered sugar
½ cup cocoa powder
2 tsp vanilla extract
4–5 tbsp milk or heavy cream
Instructions:

Beat the Butter:
In a large mixing bowl, beat the softened butter with an electric mixer until creamy and smooth.
Add Dry Ingredients:
Gradually add the powdered sugar and cocoa powder, mixing on low speed until combined.
Add Vanilla and Milk:
Add the vanilla extract and 4 tablespoons of milk or heavy cream. Beat on medium speed until the frosting is light and fluffy. If the frosting is too thick, add more milk, one tablespoon at a time, until you reach the desired consistency.
Assemble the Cake:
Layer the Cake:
Place one cake layer on a serving plate. Spread a layer of frosting on top. Place the second cake layer on top and frost the top and sides of the cake.
Decorate:
Optionally, you can decorate the cake with chocolate shavings, sprinkles, or any other toppings you like.
Serve:
Slice and enjoy your Sublime Black Velvet Treat!