Preheat oven to 350°F. Spray 13x9-inch baking pan with cooking spray. Beat cake mix, water, Egg Beaters and yogurt in medium bowl with electric mixer on low speed until well blended; beat on high speed 2 minutes. Pour into prepared pan.
Bake 30 to 35 minutes, or until wooden pick inserted in center comes out clean. Cool completely in pan on wire rack
Cut into 12 squares to serve. Top each with 2 tablespoons sliced strawberries and a serving of Reddi-wip; serve immediately.