In a small sauce pan bring the water and sugar to a light simmer over medium high heat.
Add 3 cups of the chopped strawberries and let the mixture simmer for 7-10 minutes until the strawberries have become very soft. The mixture will resemble strawberry jam.
Remove from heat and add the last cup of strawberries, stir well and set aside.
Preheat oven to 350 degrees F.
Prepare the Pillsbury Funfetti Gluten Free Cake Mix according to the package directions and turn batter into a 9x13-inch baking pan.
When cake is done, remove from oven and poke several holes in the cake (I poked 4 rows of 3) and pour the strawberry sauce over the cake and spread evenly.
Allow the strawberry sauce to sink into the cake and cool completely before frosting with the whipped cream.
Serving: 1 slice, Calories: 226kcal, Carbohydrates: 34.7g, Protein: 2.8g, Fat: 8.5g, Sodium: 216mg, Fiber: 0.8g, Sugar: 22g