Preheat oven to 350 degrees F. Lightly spray a 9x13 inch pan with pan spray.
Combine butter, E-Z Gel, water and sugars and mix until light and fluffy. Add eggs one at a time and vanilla and mix well. Combine dry ingredients and mix into creamed mixture.
Pour batter out into prepared pan and use a rubber scraper to smooth into an even layer. Sprinkle with mixed topping.
Bake for 25 minutes until tender and golden brown on the edges. Remove from oven and cool at least 15 minutes before cutting.
This recipe is great for freezing, or you can omit the topping and use it for the base for a fruit pizza.