Preheat oven to 350 degrees F. Line a 9x13 baking pan with a piece of parchment paper. Let the parchment paper drape over two sides of the pan. This will help you pull the bars out of the pan after they're cooled.
In a mixing bowl, add in the butter and sugar. Mix until light and fluffy. It will take a minute or two.
Add in the vanilla and flour and mix on medium until combined and forms a dough ball.
Press the shortbread into the bottom of the prepared pan. Make sure it's evenly spread out and touches all edges.
Apple Pie Filling
In a large bowl, add in the flour, sugar and cinnamon. Whisk to incorporate.
Add in the sliced apples and vanilla. Stir until the flour and sugar mixture covers every apple.
Layer the apples on the shortbread so they're neatly packed into the bars.
In a mixing bowl, add in the butter, brown sugar, vanilla, salt and flour. Using a pastry cutter, cut the butter into the flour until crumbs form.
Sprinkle the crumbs on top of the apple pie mixture trying to cover most of the apple pie filling.
Place into the oven and bake for 50 minutes or until the crumbs are golden brown.
Let the bars cool completely. I chilled mine in the fridge overnight to get the perfect square cuts.
Cut and serve. Add a scoop of vanilla ice cream for an extra delicious bite.
Apple Pie Crumb Bars https://www.cookiedoughandovenmitt.com/apple-pie-crumb-bars-3/