Preheat and Prepare: Preheat your oven to 350°F (175°C). Grease and line two 9-inch round cake pans with parchment paper.
Mix Dry Ingredients: In a large bowl, sift together flour, cocoa powder, sugar, baking powder, baking soda, and salt.
Combine Wet Ingredients: Add eggs, milk, oil, and vanilla extract to the dry ingredients. Beat on medium speed until smooth and well-combined.
Add Boiling Water: Reduce speed to low and carefully stir in boiling water. The batter will be thin, but this is normal.
Bake: Divide the batter evenly between the prepared pans. Bake for 30–35 minutes or until a toothpick inserted in the center comes out clean.
Cool: Let the cakes cool in the pans for 10 minutes, then transfer them to a wire rack to cool completely.
For the Frosting:
Cream Butter: In a mixing bowl, beat the softened butter until creamy.
Add Dry Ingredients: Gradually sift in powdered sugar and cocoa powder. Beat until fully combined.
Flavor and Texture: Add salt, vanilla extract, and 4 tablespoons of heavy cream. Beat until fluffy. Add more cream if needed for a spreadable consistency.
Assemble the Cake:
Level the Cake: If needed, level the top of the cakes using a serrated knife.
Layer and Frost: Place one cake layer on a serving plate, spread frosting evenly on top, then add the second layer. Frost the top and sides.
Decorate: Add sprinkles, chocolate shavings, or any decorations of your choice.
Serve: Slice and enjoy your homemade chocolate cake!