Preheat oven to180C. Line 2, 8-inch cake rounds with parchment paper and oil your pans, set aside.

In a large mixing bowl, cream together the softened butter and sugar until light and fluffy. Add the eggs and vanilla and beat again until creamy.

In a separate bowl, combine the dry ingredients: flour, baking powder and salt. Stir them together, then add the dry ingredients into the cake batter. Pour in the milk, then whisk everything together by hand, just until combined; don't over-mix the batter.

Melt the 1/2 cup white and dark chocolate in the microwave or over a double boiler. Divide the cake batter in half between 2 mixing bowls. Add the melted dark chocolate into one bowl, the melted white chocolate into the second. Mix the chocolate into the cake batter until well combined.

Pour the cake batter into the prepared pans. Bake in preheated oven for 40 to 45 minutes, or until a toothpick inserted into the center comes out clean. Allow the cakes to cool slightly into the pans, then invert onto a cooling rack to cool completely.

Assemble the checkered cake. Split each cake layer in half. Use 6-inch and 2-inch round cookie cutters to cut each layer into 3 pieces. Swap out the center and outer rings.

Assemble the cake with alternating layers, spreading frosting between each layer. Frost the top and sides; smooth down with a flat spatula.