Heat the oven to 350 F and line a 12-cup muffin pan with paper liners.
Stir the rolled oats, almond flour, brown sugar, melted butter, and cinnamon together until small clumps form. Set the crumble aside.
Blend the cottage cheese, eggs, maple syrup, melted butter, and vanilla extract until smooth and creamy.
Whisk the oat flour, protein powder, baking powder, baking soda, and salt in a large bowl. Add the blended cottage cheese mixture and stir just until combined.
Gently fold the blueberries into the batter, then divide it evenly among the prepared muffin cups.
Sprinkle the crumble over the muffins. Bake for 21 to 25 minutes, until the tops spring back lightly and the centers are set.
Cool the muffins in the pan for 10 minutes, then transfer them to a cooling rack and let them cool for at least 20 minutes before serving.
