Preheat the oven to 350 degrees. Grease two 6-inch round cake pans and line the bottoms with parchment.

In a mixing bowl, cream the softened butter and sugar until light and fluffy. Add the eggs one at a time, beating well after each addition.

Stir in the vanilla extract. In a separate bowl, whisk together the flour and baking powder.

Add the dry ingredients to the butter mixture in two parts, alternating with the milk. Mix until the batter is smooth.

Divide the batter evenly into three bowls. Leave one bowl plain, tint the second bowl yellow, and tint the third bowl orange.

Pour the yellow batter into one prepared pan and the orange batter into the other. Bake for 22 to 25 minutes, or until a toothpick comes out clean.

Let the layers cool in the pans for 10 minutes, then remove them to a wire rack to cool completely. Slice each cooled layer in half horizontally to create three thin layers total.

Place the yellow layer on a plate and spread a thin layer of buttercream frosting on top. Add the plain white layer and repeat with frosting. Top with the orange layer.

Spread the remaining buttercream over the top and sides of the cake. Press candy corn pieces around the top edge to finish.