Blueberry Poke Cake

1. Preheat the oven to 350 degrees F (175 degrees C). Grease and lightly flour a 9x13-inch baking pan.

2. Combine cake mix, cake mix extender, 1 1/4 cups water, egg whites, and oil together in a large bowl; beat with an electric mixer on low speed until moistened. Pour batter into the prepared pan.

3. Bake in the preheated oven until a toothpick inserted into the center comes out clean, 32 to 36 minutes.

4. While cake is baking, combine sugar and cornstarch together in a small saucepan. Stir in remaining 1 cup water and bring to a boil over medium heat, stirring constantly. Add blueberries and lemon juice; cook and stir until blueberries burst and sauce turns a deep purple color, about 10 minutes. Gently mash any berries that did not burst. Remove from heat and let cool until cake is ready.

5. Transfer cake to a wire rack; cool to room temperature, at least 25 minutes.

6. Poke holes into the cake about every inch with the handle of a wooden spoon. Slowly pour blueberry sauce over cake. Refrigerate until cool before slicing.

Cook's Note:

The directions for making the cake are based on the particular brand mentioned. Follow instructions on the box if using a different brand. Some cake mixes are 15.25 ounces and some are 16.25, so add the appropriate amount of extender needed to reach 18.25 ounces. For the extender, you can use boxed cake mix or your favorite cake extender recipe.