Preheat the oven to 180°C. Grease and line two 8-inch round cake pans with parchment paper.
In a large bowl, mix 250 grams of all-purpose flour, 400 grams of sugar, 75 grams of cocoa powder, 1 1/2 teaspoons of baking powder, 1 1/2 teaspoons of baking soda, and a pinch of salt.
Add 2 large eggs, 240 ml of milk, 120 ml of vegetable oil, and 2 teaspoons of vanilla extract to the dry ingredients. Mix well until combined.
Slowly pour in 240 ml of boiling water and mix until the batter is smooth. Divide the batter evenly between the two prepared cake pans.
Bake for 30-35 minutes or until a toothpick inserted in the center comes out clean. Allow the cakes to cool in the pans for 10 minutes, then transfer them to a wire rack to cool completely.
Prepare the chocolate frosting by mixing 200 grams of softened unsalted butter, 400 grams of powdered sugar, 75 grams of cocoa powder, 60 ml of milk, and 2 teaspoons of vanilla extract until smooth and creamy.
Place one cake layer on a serving plate and spread a layer of chocolate frosting on top. Place the second cake layer on top and cover the entire cake with the remaining frosting.
Break 20-25 KitKat bars into individual fingers and press them vertically around the sides of the cake, making sure they stick to the frosting.
Tie a ribbon around the cake to secure the KitKat bars. Fill the top of the cake with your choice of chocolate candies or sprinkles.