Preheat your oven to 350°F (175°C). Grease two 9-inch round cake pans and line the bottoms with parchment paper.

In a large mixing bowl, whisk together the flour, sugar, cocoa powder, baking powder, baking soda, and salt.

Add the eggs, milk, vegetable oil, and vanilla extract to the dry ingredients. Mix until well combined and smooth.

Slowly pour in the boiling water and mix until the batter is thin and evenly combined.

Fold in the white chocolate chips and semi-sweet chocolate chips to create the ‘polka dot’ effect in the batter.

Divide the batter evenly between the prepared cake pans and smooth the tops.

Bake for 30-35 minutes, or until a toothpick inserted into 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.

To make the ganache, heat the heavy cream in a small saucepan over medium heat until it begins to simmer. Remove from heat and pour over the chopped semi-sweet chocolate in a heatproof bowl. Let sit for 2 minutes, then stir until smooth.

Once the cakes are fully cooled, place one layer on a serving plate. Spread a thin layer of ganache over the top. Add the second layer and spread ganache over the top and sides of the cake.

Decorate the cake with colorful candy-coated chocolate pieces arranged in a polka dot pattern. Press them gently into the ganache so they stick.

Let the cake sit for about 30 minutes to allow the ganache to set before serving.