Preheat oven to 325°F. Prep your cake rounds by covering the inside of the pans with a light layer of butter and then dusting with flour. I like to use my fingers to make sure the butter gets in all seams.

Mix together, either by hand or in a stand mixer, the oil, vanilla, sour cream, heavy cream and egg whites. Then mix in the boxed cake mix. Mix until only just combined- overmixing will cause the cake to sink in the middle. Gently stir in the crushed candy canes if using.

Divide the batter between the 3 cake rounds.

Bake for 25 minutes or until a toothpick inserted comes out clean. Make sure to bake all the cakes on the same oven rack so they bake evenly.

Let the cakes cool for 5 minutes then flip upside down onto a wire cooling rack and remove the pans. They should come out easily.

Let the cakes cool completely before frosting.

Whip up 2 batches of my Vanilla Butter Cream frosting, divide into two bowls.

In one bowl stir in M&Ms, leaving the other bowl as just plain frosting.

Scoop about ½ cup of M&M frosting onto the bottom layer of the cake and smooth into an even layer.

Place the second cake layer on top and then use the rest of the M&M frosting to make a crumb coat on the cake. The crumb coat won’t be very smooth since there are M&Ms in it but that’s okay because our piping will cover it up.

Once the crumb coat is on place the cake in the refrigerator for 10 minutes to let it harden slightly.

After 10 minutes pipe on the rosettes using the 1M piping tip. Decorate the top with extra M&Ms and fun sprinkles.

Enjoy!