Mix warm milk with sugar and yeast in a medium bowl. Allow to stand for about 10 minutes, until it becomes foamy.

Mix the all-purpose flour, buckwheat flour, oats, cinnamon and salt in a large bowl. Add yeast mixture to flour-oat mixture, stirring to combine. The batter will be very thick. Cover with plastic wrap. Let sit at room temperature for one hour or refrigerate for a few hours or overnight.

Preheat oven to 200 degrees F. Place a cooling rack on top of a baking sheet.

Preheat Belgian waffle iron.

Using a mixer, beat the egg whites until they are frothy. Pour the melted butter over the top of the yeasty batter and mix in with a whisk. Fold in the egg whites, and right before they’re totally incorporated, sprinkle the baking powder over the batter and mix in.

Brush the surfaces of the waffle iron with a bit of butter.

Pour about 1 cup of batter onto the waffle iron. If necessary, spread it with a spatula, then close the iron and allow to bake until the waffle is golden and thoroughly cooked, about 4-5 minutes. Transfer the cooked waffle to the cooling rack and place in warm oven.

Repeat to make remaining waffles.

Serve waffles with sliced bananas, strawberries, and almonds (or fruit and nuts of your choice) as well as warm maple syrup.