Following the directions on the box, prepare white cake mix batter and divide equally into three different bowls. Using food coloring, color one bowl yellow, one orange, and leave the third white.
Grease a 9 x 13 cake pan and spread the yellow cake batter evenly across the bottom. Put the pan in the freezer on a straight rack for 25 minutes.
Remove the pan from the freezer and carefully pour the orange layer of cake batter into the pan, gently spreading the batter creating and even layer that completely covers the yellow batter. Put pan back into the freezer for 25 more minutes.
Remove the pan from the freezer once more and carefully spread the white cake mix batter over the orange batter, evenly. Place the pan on top of the preheating oven for 1/2 hour to warm up the frozen batter. This will allow the batter to cook and rise evenly in the oven.
Remove the cake from the oven once cooked and immediately poke holes throughout the cake with toothpicks or skewers. Pour the sweetened condensed milk evenly over the cake.
Once the cake has chilled whip beat the heavy whipping cream with sugar (according to desired sweetness) and spread evenly over the top of the cake. Decorate with candy corn and serve!