This is great! Make sure you wait until you’re ready to serve before adding the crushed root beer candy. The prep time includes cooling time. Oh yeah, this is great with a cold glass of root beer on the side.
Heat oven to 350°F Grease bottom only of 13 x 9 x 2-inch pan.
Beat cake mix, water, oil, and egg whites in large bowl with electric mixer on low speed for 30 seconds; move to medium speed for 2 minutes. Reserve 1 cup of batter.
To the reserved batter, add the allspice and cinnamon; stir and set aside. Pour remaining batter into pan.
Drop the reserved batter by tablespoons all around the batter in the pan (about 12 to 14 mounds); swirl the batter together in an “S” shape.
Bake 28 to 33 minutes or until toothpick inserted in center comes out clean. Cool completely for 1 hour. After cake is cooled, make frosting.
Beat all the ingredients of the frosting together in a chilled bowl until soft peaks form. Frost the cake. Just before serving, sprinkle each piece with crushed root beer candies. Store covered in refrigerator.