1 (18.25 ounce) package white cake mix
1 1/4 cups water
1/3 cup vegetable oil
3 egg whites
8 drops red food coloring
2 drops raspberry candy oil
1. Preheat an oven to 350 degrees F (175 degrees C). Line a standard muffin tin with paper cupcake liners.
2. Beat the cake mix, water, vegetable oil, and egg whites together on low speed for 30 seconds, then on medium for 2 minutes, until smooth. Fill cupcake liners 1/3 full with white batter; set aside.
4. Stir 4 drops of red food coloring into the remaining bowl of batter to make the batter pink, stir in the raspberry oil. Pour 1/3 of pink batter into a resealable plastic bag and set aside.
5. Cut the corner off the bag with the pink batter, stick the open tip into the center of the red batter and squeeze about 1 tablespoon pink batter into each cup.
6. Bake the layered cupcakes in the preheated oven until a toothpick inserted into the center comes out clean, 15 to 20 minutes. Cool completely before frosting.