Preheat your oven to 350°F (175°C). Line an 8x8 inch baking pan with parchment paper.

Mix dry ingredients: Combine gluten-free oat flour, rolled oats, brown sugar, ground cinnamon, baking soda, and salt in a large mixing bowl.

Incorporate wet ingredients: Add melted butter (or vegan butter) and vanilla extract. Stir until crumbly and clumping together.

Form the crust base: Press two-thirds of the crumble mixture into the bottom of the prepared pan.

Cook the apples: In a skillet, combine sliced Honeycrisp apples, butter, maple syrup, and cinnamon. Cook for about 5-7 minutes.

Assemble the bars: Pour the apple filling over the crust and sprinkle the remaining crumble mixture on top.

Bake for 30-35 minutes until golden brown and bubbly. Let cool for at least 15 minutes.

Prepare the caramel sauce: Mix peanut butter, maple syrup, coconut oil, vanilla extract, and salt in a microwave-safe bowl. Heat in the microwave until smooth.

Drizzle caramel over the cooled bars before cutting into squares and serving.