Preheat the waffle iron. Preheat the waffle iron and spray with non-stick cooking spray.
Combine the dry ingredients. In a large mixing bowl, combine all dry ingredients (flour, sugar, salt, and baking powder) and stir until thoroughly combined.
Combine the wet ingredients. Whisk together the wet ingredients (eggs, buttermilk, vegetable oil) in a separate medium bowl.
Mix the batter. Add the wet ingredients to the dry ones and mix gently until just combined. The batter may have some lumps, but there shouldn't be any dry spots.
Fold in blueberries. Gently fold in the blueberries until evenly distributed.
Cook the waffles. Scoop the batter into the hot waffle iron, about a half cup at a time, depending on the size of your iron. Cook until golden brown.
Serve. Serve with syrup and butter or with whipped cream and additional blueberries.