These lemon blueberry cake bars make such a simple dessert using Duncan Hines cake mix and various fresh flavors to give a sweet and tart flavor.

Ingredients used

For the brownies
* 1 box (15.25 oz) Duncan Hines lemon cake mix
* 2 large eggs
* 1/3 cup melted unsalted butter
* 1 teaspoon lemon extract
* 1 teaspoon vanilla extract
* 1/2 cup whole milk
* Zest of 1 whole lemon
* 1/2 cup fresh blueberries

For the glaze

2 cups powder sugar
3 - 3 1/2 Tbsp freshly squeezed lemon juice
1/2 tsp vanilla extract
1/2 tsp Lemon zest
1 tsp blueberry jelly