Preheat your oven to 350°F.
Prepare a 9x13-inch baking pan by greasing it with cooking spray and lining it with parchment paper.
In a large bowl, beat the butter, granulated sugar, and vanilla extract until airy and light.
Add the all-purpose flour and salt to the mixture, blending until combined and the dough forms.
Press about 3/4 of the dough mixture into the bottom of the prepared pan, creating an even layer.
In another bowl, toss the sliced apples with ground cinnamon until they are well coated.
Layer the cinnamon-coated apple slices evenly over the pressed dough in the baking pan.
Crumble the remaining dough over the apple layer, making sure to cover as much of the apple filling as possible.
Place the pan in the preheated oven and bake for 45-50 minutes or until the top is golden brown and the apples are tender.
Remove the pan from the oven and let it cool completely before cutting into bars.