Preheat the oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.

In a mixing bowl, combine flour, sugar, cocoa powder, baking powder, baking soda, and salt.

Add eggs, milk, oil, and vanilla extract. Mix until well combined.

Divide the batter evenly between the prepared pans.

Bake for 30 minutes or until a toothpick inserted into the center comes out clean.

Let the cakes cool in the pans for 10 minutes, then transfer to a cooling rack to cool completely.

In a mixing bowl, beat the softened butter until creamy.

Gradually add powdered sugar and cocoa powder, mixing until combined.

Add vanilla extract and milk, and beat until smooth and fluffy.

Once the cakes are completely cool, place one layer on a serving plate.

Spread a layer of frosting on top of the first cake layer.

Place the second cake layer on top and frost the entire cake with the remaining frosting.

Roll out green fondant and cover the top and sides of the cake to create Frankenstein's face.

Use black fondant to create hair and attach it to the top of the cake.

Shape white fondant into eyes and place chocolate chips as pupils.

Use red fondant to create stitches on the face.