In an electric mixer, or a large bowl, add the cereal crumbs. In the same unwashed blender, add 2 cups of strawberries and puree them. Add the pureed strawberries to the bowl of crumbs. Mix in egg whites, eggs, and canola oil. Add both sugars, flour, oats, baking soda and salt. Mix until combined. Finally, add 2 cups sliced strawberries and walnuts. Mix batter until combined but not over mixed.