Line two 9-inch round cake pans with wax paper. Spray with nonstick spray. In a large bowl, beat cake mix, jello, egg whites and canola oil. Mash strawberries and reserve 3 T. for icing. Add remaining mashed strawberries and water and mix well. Pour into prepared cake pans and bake at 350 for 20-25 minutes or until a toothpick inserted near the center comes out clean. Cool in pans for 10 minutes and then remove to wire racks to cool completely.
For icing, beat powdered sugar, butter and strawberry juice. Frost cake.