Preheat the oven to 350 degrees {or per package directions}. Grease two 9-inch cake pans and set aside.

Mix together cake mix, eggs, oil and water. Mix on medium speed for 2 minutes. Divide between the prepared pans and bake according to package directions. Remove from oven and cool completely.

In a small saucepan, add strawberries, 1/4 cup water and 1 1/4 cup sugar. Bring to a boil and then reduce heat to low. Simmer until reduced by half and thickened. Let cool.

In a separate saucepan, add blueberries, 1/4 cup water and 1 1/4 cup sugar. Bring to a boil and then reduce heat to low. Simmer until reduced by half and thickened. Let cool.

Place one cake on cake stand. Spread half of cool whip on top. Pour cooled blueberry mixture on top of cool whip and spread evenly. Top with second cake layer. Add remaining cool whip and top with strawberry mixture. Garnish with extra strawberries and blueberries if desired.