For the Shortbread Base:

1. Preheat the oven to 3o0˚F. Spray a 8x8 inch square pan with cooking spray and line the inside with parchment paper. Set it aside.
2. Beat the butter and granulated sugar together with a rubber spatula until fluffy. Then mix in the flour, cornstarch, and salt until combined. Place the dough into the prepared pan. Spread and press the dough out into a flat even layer, covering the entire bottom of the pan.
3. Bake it in the oven for 20 minutes. Remove it from the oven and increase the oven temperature to 350˚F.

For the Apple Strawberry Filling:

1. Add all of the ingredients into a bowl and mix until well combined. Evenly spread the mixture on top of the baked shortbread base.

For the Crumble Topping:

1. Add the flour, brown sugar, granulated sugar, cinnamon, salt, and That’s It Bars to a bowl. Mix until combined. Pour in the melted butter and mix until it looks like wet sand.
2. Use your hands to squeeze the dough together. Then allow it to crumble into pieces over the apple strawberry filling layer. Continue to crumble the topping all over the top of the filling.
3. Bake the bars in the oven for 30-35 minutes until the crumble topping turns golden brown. Remove the pan from the oven and allow the bars to cool to room temperature in the pan. When completely cooled, cut the bar into squares. Enjoy!