Combine yeast with water and sugar and let sit for 5 minutes or until the mixture becomes foamy and the yeast is activated. In a large bowl, combine flour and salt. Add yeast mixture and melted butter, milk, and rosewater. Mix until a shaggy dough forms. Cover with plastic wrap and let it rest at room temperature overnight.

The next day, add beaten egg and baking soda to the batter. Gently stir in the blueberries. Cook the waffles in waffle maker until golden brown. Remove and repeat with remaining batter. Serve with a dollop of Greek yogurt, and maple syrup.