1. Preheat your oven to 350°F and line a 9×13 inch baking pan with parchment paper.

2. In a large bowl, mix together the flour, granulated sugar, and salt. Cut in the cold butter until the mixture resembles coarse crumbs. Press two-thirds of this crumb mixture into the bottom of the prepared baking pan.

3. Pop the crust in the oven and bake it for 15 minutes, or until it’s lightly golden. Once baked, let it cool slightly while you prepare the filling.

4. While the crust is baking, toss the sliced apples with the brown sugar, cinnamon, nutmeg, cornstarch, lemon juice, and vanilla extract in a separate bowl.

5. Spread the apple mixture evenly over the baked crust. Then, sprinkle the remaining crumble mixture on top.

6. Return the pan to the oven and bake for 35–40 minutes, until the top is golden brown and the apples are tender. Keep a close eye to prevent the edges from burning.

7. Once the Apple Pie Bars are out of the oven, let them cool completely in the pan. When cooled, use the parchment paper overhang to lift the bars out of the pan and slice them into perfectly portioned squares.