Preheat oven to 180°C
In a bowl mix together yoghurt, maple syrup, eggs, and milk
Add oats, oat flour, baking powder, and cinnamon to the wet ingredients
Mix until just combined
Pour into a prepared baking tin
Mix together cinnamon swirl ingredients (cinnamon, melted butter, and maple syrup)
Drizzle cinnamon swirl mixture over the cake batter
Use a knife to make swirls through the batter
Bake for 20 minutes or until a toothpick comes out clean
