Preheat the oven to 325 degrees F. Grease an 8-by-8-inch baking pan with gluten-free cooking spray. Line the pan with an overhanging piece of parchment paper to easily remove the bars.
Place the apples, walnuts, chopped and sliced almonds, flaxseed meal, puffs cereal, hemp seeds, protein powder, cinnamon, salt, rice syrup and maple syrup in a large bowl. Stir to combine and evenly coat. Transfer the apple mixture to the prepared pan and, using a greased piece of parchment paper, press down firmly to spread evenly. Bake until just firm, about 12 minutes. Let cool completely on a rack.
Reduce the oven temperature to 250 degrees F. Line a rimmed baking sheet with parchment paper and place a wire rack on top. Remove the apple bar from the pan and cut evenly into 12 bars. Place, gooey-side up, on the wire rack. Bake until almost dry to the touch, about 15 minutes. Let cool completely on a rack.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.