Sweetheart Cake

Heat oven to 350°F (see Tips). Grease or lightly spray bottom and sides of one 8-inch round cake pan and one 8-inch square pan.

In large bowl, beat cake mix, water, oil, and egg whites with electric mixer on medium speed for 2 minutes, scraping bowl occasionally. Divide batter evenly between the pans.

Bake the square pan for 22 to 26 minutes and the round pan for 26 to 31 minutes or until toothpick inserted in center comes out clean. Cool 10 minutes; remove from the pans to a cooling rack. Cool completely, about 1 hour.

Using a serrated knife, cut the round cake in half to create two semicircles. (See link for diagram above.)

Place the square cake on a tray or serving platter with one corner pointing down toward you. Place the cut side of each semicircle against one of the top sides of square cake to make a heart. 

In a medium bowl, mix the frosting with a few drops of the red food color until blended. Add additional food color until desired shade of pink is reached. Frost cake with the frosting. Store loosely covered at room temperature.