Put the oats in a food processor and process until the oats look like flour. Place oat flour, baking soda, baking powder, cinnamon, nutmeg and salt in a medium bowl and whisk together. Set aside.

In a separate bowl, beat egg until light and foamy. Add vanilla, milk, and mashed banana and whisk to combine. Pour the wet ingredients into the dry ingredients and stir, using a wooden spoon or rubber spatula, until just combines. Gently stir in the chopped cranberries.

Heat a large non-stick pan over medium heat and spray with cooking spray. Pour 1/4 cup of batter for each pancake into the pan. Cook until the edges look dry and bottoms are golden; flip and cook on the other side until cooked through.

Serve warm with a drizzle of maple syrup and sliced banana.