Preheat oven to 350F and spray a 12 hole regular size muffin tin with some non stick cooking spray.In a bowl whisk together the egg and sugar, stir in milk, applesauce, yogurt and vanilla.Mix in the flour and baking powder, then slowly fold in the blueberries.Divide the batter over the 12 muffin cups and bake for approximately 22 minutes or until baked through.Let cool.. makes 12 muffins, best store in a sealed container and/or in the fridge