Mix together the flour, undissolved yeast, sugar, salt and cinnamon in a large bowl or the bowl of your stand mixer. Add the milk, eggs, melted butter and vanilla, stirring just until blended.
Cover with plastic wrap and refrigerate overnight.
Remove batter from refrigerator and stir down batter. Add blueberries and stir gently.
Preheat waffle iron and cook waffles according to manufacturer's directions.
Serve immediately with your favorite toppings.
Notes
You can skip the overnight method and let the covered batter rise in a warm, draft-free place for 45 minutes until doubled.
Recipe by Mandy's Recipe Box at https://mandysrecipeboxblog.com/overnight-blueberry-waffles/