Preheat your oven to 350°F (180°C) with a fan assistance feature for an even bake. Prepare a 6-inch cake tin by lining it with parchment paper for easy removal.

In a large mixing bowl, carefully sift together the all-purpose flour, granulated sugar, cocoa powder, baking powder, and a pinch of salt.

In a separate bowl, beat the eggs until they’re frothy and well combined. Add the beaten eggs, milk, and black gel food color to the dry mixture, combining thoroughly.

Pour the thick and dark batter into the prepared tin, smoothing the top gently.

Bake for 35-40 minutes, watching closely after 30 minutes; the cake is done when a toothpick inserted into the center comes out clean.

Once baked, remove the cake from the oven and transfer it to a cooling rack. Allow it to cool completely before removing it from the tin.

In three medium bowls, set aside for different colors. Melt the white chocolate in a microwave or a double boiler.

In a saucepan over medium heat, bring the heavy cream to a simmer, ensuring it doesn’t boil. Pour the warm heavy cream over the melted white chocolate.

Divide the white chocolate ganache into three portions, then add green gel food color to one portion, orange to another, and purple to the last.

Slice the cooled cake into three even layers. Spread the green frosting on the first layer, then top with the orange frosting on the second layer, and finish with the purple frosting on the top layer.

Decorate with spooky decorations like edible eyes, candy pumpkins, or any other Halloween-themed toppings.