Directions

Preheat your oven to 350°F (175°C) and line a 9×13 inch baking dish with parchment paper.
In a large bowl, mix together the melted butter, granulated sugar, vanilla extract, and salt until well combined.
Add the flour to the butter mixture and stir until crumbly. Reserve 1 cup of this mixture for the topping.
Press the remaining crumb mixture evenly into the bottom of the prepared baking dish to form the crust.
In another bowl, combine the diced apples, brown sugar, cinnamon, lemon juice, and cornstarch. Mix until the apples are well coated.
Spread the apple mixture evenly over the crust in the baking dish.
Sprinkle the reserved crumb mixture over the top of the apples.
Bake in the preheated oven for 35-40 minutes, or until the top is golden brown and the apples are tender.
Allow the bars to cool in the pan before cutting into squares and serving.
Variations & Tips

For a nutty twist, add 1/2 cup of chopped walnuts or pecans to the crumb topping. You can also experiment with different types of apples for varied flavors and textures; Granny Smith apples add a tartness, while Honeycrisp apples offer a sweet and juicy bite. If you prefer a spicier flavor, consider adding a pinch of nutmeg or allspice to the apple mixture.