Preheat the oven to 175 degrees Celcius. Place the iron skillet in the oven with some coconut oil in it and let it get hot while you prepare the batter.
Mix eggs until a little fluffy.
Add the quark, mashed banana and stevia vanilla drops and mix again.
Combine oat flour, baking powder, cinnamon and salt to a bowl and stir to combine. Add little by little to the batter and mix until combined. Taste to check if you prefer it sweeter and add stevia granulated sugar according to taste.
Add the raspberries and fold in.
Take out the iron skillet from the oven and pour the batter to the pan. Place back in the oven and bake for 16-20 minutes, until golden brown.
Remove from the oven and serve immediately.