1. Preheat oven to 350 degrees. Line 18- 2 1/2 inch muffin cups with paper baking cups. 2. In a large bowl, combine cake mix, milk, oil, egg whites; beat with an electric mixer on low speed for 30 seconds. Usind a rubber spatula, scrape down the sides of the bowl and beat on medium speed for 2 minutes more. Remove 1 cup of the batter and transfer to a small bowl; add strawberry preserves, 1/4 tsp. of the strawberry extract, and 8 drops of the food coloring, stirring until well mixed. Fill each prepared muffin cup tith 1 Tbsp. of the strawberry batter, about 2 Tbsp. of the white batter and another 2 tsp. of the strawberry batter. Run a toohtpick through each batter-filled cup to swirl batter. 3. Bake in preheated oven for 16 to 20 minutes or unitl toothpick inserted in center comes out clean. Remove from muffin cups; cool on wire racks. 4. For strawberry frosting, stir the remaining 4 drops red food coloring into 1 of the cans of frosting. Insert large round tip into large pastry bag. Lay pastry bag on a counter and fill one side of bag with vanilla frosting. Carefully fill the other side of bag with strawberry frosting and secure top of bag. Pipe a large swirl of two-tone colored icing on top of each cupcake.