Start by making the apple pie filling: melt the butter in a saucepan over medium heat. Toss the remaining ingredients for apple pie filling in a mixing bowl and add it to the saucepan. Cook until the sugar dissolves completely and the apple pieces are just starting to soften, about 5 minutes. Take off the heat and set aside to cool.

Preheat the oven to 350°F.

Grease an 8”x8” square baking pan with nonstick spray or melted butter, and line it with a long piece of parchment paper letting the excess hang over the sides of the pan and set aside.

Cream together the softened butter, brown sugar and vanilla extract in a stand mixer bowl with the paddle attachment until light in color.

Stir together flour, rolled oats, apple pie spice and salt in a mixing bowl until evenly distributed. Add the flour mixture to the butter mixture and stir until a dough forms.

Take about ⅔ - ¾ of the dough and press it into the bottom of the prepared pan. Add the cooled apple pie filling on top. Sprinkle chunks of the remaining dough over the pie filling.

Bake for 35 - 40 minutes until the crumb topping is lightly brown and the filling is bubbly and caramelized.

Remove from the oven and allow it to cool completely on a wire rack before removing it from the pan and cutting into bars.