Mix sourdough starter, buttermilk, oat flour, flaxmeal and maple syrup until combined. Cover with a cloth and let sit on the counter for 8-12 hours - or overnight.
The next morning:
Whisk together the butter and eggs. Add to the sponge.
Sprinkle the baking soda and salt on top of the batter. Mix until incorporated.
Preheat your waffle iron. Follow the instructions included with your waffle iron.
Enjoy with berries, syrup and whip cream!
Notes:
*Use an active gluten-free sourdough starter that is fed at least 8 hours beforehand