Preheat the oven to 350°F (175°C) and prepare an 8x8 or 9x9 baking pan by lining it with parchment paper for easy removal.

Combine almond flour, gluten-free rolled oats, and optional cinnamon in a large mixing bowl and stir until well mixed.

Mix in the maple syrup and melted coconut oil until thoroughly incorporated.

Fold in the apples and blueberries gently, ensuring even distribution.

Spread the mixture evenly in the prepared pan, smoothing the top with a spatula.

Bake for 25-30 minutes, or until the top is golden brown and slightly firm to the touch.

Cool completely in the pan, then transfer to a cutting board, slice into bars, and store in an airtight container.