Preheat Oven: Set your oven to 350°F (175°C). Line two muffin tins with 18 paper liners.
Prepare Cake Batter: In a large bowl, combine the cake mix, egg whites, vegetable oil, water, and cotton candy flavoring. Mix until smooth, about 2 minutes. Divide the batter evenly into two separate bowls. Add blue food coloring to one bowl and pink to the other, mixing until well incorporated.
Fill Muffin Cups: Distribute the batter into the muffin cups, layering the blue and pink batters without swirling them together. Fill each cup about 3/4 full.
Bake: Place the muffin tins in the preheated oven and bake for 15-18 minutes, or until a toothpick comes out clean. Let the cupcakes cool completely.
Make Frosting: In a medium bowl, cream together the softened butter, cotton candy flavoring, and vanilla extract. Gradually add confectioners’ sugar, alternating with heavy cream, until fluffy. Divide the frosting into two bowls. Tint one blue and the other pink.
Pipe Frosting: Fit a pastry bag with a large star tip. Spoon the blue frosting down one side and pink on the other. Pipe the frosting onto the cooled cupcakes in a swirl pattern.
Decorate: Sprinkle the frosted cupcakes with sanding sugar. Attach small pieces of cotton candy to wet popsicle sticks and place them on top of each cupcake.