1Heat oven to 350°F. Spray bottom of 13x9-inch pan with cooking spray. In large bowl, beat cake mix, water, oil and egg whites with electric mixer on low speed 30 seconds. Beat on medium speed 2 minutes, scraping bowl occasionally. Pour into pan.
2Bake 28 to 32 minutes or until toothpick inserted in center comes out clean. Cool on cooling rack 20 minutes.
3Meanwhile, in medium bowl, pour boiling water on gelatin; stir until gelatin is dissolved. Poke cake every inch with handle of wooden spoon or tines of meat fork halfway into cake. Carefully pour strawberry gelatin evenly over top of cake. Cool completely, about 1 hour.
4Spread frosting over top of cake. Drizzle red decorating gel over frosting. Cut into 4 rows by 3 rows. Garnish each piece of cake with strawberries.