Preheat oven to 350. Line a 24-cup mini muffin tin (or a 12-cup regular sized tin) with muffin cups.
Mash banana, and peel and chop apple into small pieces.
In a large bowl, combine flour, oats, flaxseed, 1/2 TSP cinnamon, 6 TBSP brown sugar, baking powder, nutmeg and salt.
Add melted butter, almond milk, and mashed banana, and mix together.
Add chopped apple, and mix well.
Spoon batter into muffin cups.
In a small bowl, mix together remaining 1 TBSP sugar and 1/2 TSP cinnamon. Sprinkle evenly on top of each muffin.
Bake until lightly browned and a toothpick comes out clean, around 15 minutes.
Allow to cool slightly before enjoying.