Start by preheating your oven to 375°F. Line a muffin tin with paper liners or grease well with oil to ensure your muffins come out smoothly.
In a medium bowl, whisk together the almond flour, tapioca flour, collagen or protein powder, baking powder, salt, and apple pie spice.
Add the maple syrup, oil, and eggs until well combined. Gently fold in the finely chopped apples.
For the crumble topping, combine the almond flour, maple syrup, oil, and apple pie spice in a small bowl. Mix until it forms a crumbly texture.
Spoon the muffin batter into the prepared muffin tin, filling each cup all the way full (about a ¼ cup of batter each). Top each muffin with a generous amount of the crumble mixture.
Bake in the preheated oven for 15 minutes, then without opening the oven, reduce heat to 350 degrees and bake another 15 minutes, or until the tops are solid to the touch. Let the muffins cool in the tin for about 5 minutes before transferring to a wire rack to cool completely.
Keep them in an airtight container at room temperature for up to 4 days, with a paper towel underneath them and on top of them to absorb moisture, or in the fridge for up to a week.
TO FREEZE: Freeze in a single layer until frozen, then store them in a sealed zip top bag or container for up to 3 months.
