Set oven to 350°F. Line an 8 x 8-inch baking pan with parchment paper and set aside.
Melt the butter in the microwave; let it cool to room temperature. In a large bowl, use a hand mixer to beat together all crust and topping ingredients until a thick dough forms. Use your hands to knead ingredients together if needed.
Press 1-1/2 cups of the dough into the base of the prepared pan, making an even layer. Bake for 7 minutes, then remove from the oven.
In a separate bowl, gently mix together the apple filling ingredients. Sprinkle the apple mixture evenly over the crust—do not press down.
Crumble the remaining dough over the apples. Do not press down. Bake for 30–35 minutes until the edges are golden brown and the top is set.
Allow the bars to cool for 1 hour at room temperature before cutting. These bars are best enjoyed warm, ideally on the same day. For a special treat, serve with vanilla bean ice cream and caramel sauce.
Video
Notes
Storage: Store the bars in an airtight container at room temperature. They are best enjoyed the same day, as they can become mushy after that. These bars do not freeze well.