Preheat oven to 350 degrees. Generously grease and flour a donut pan then set aside.
Sift flour, baking powder, baking soda, granulated sugar and brown sugar together in a large bowl.
In a separate bowl, whisk egg, buttermilk, yogurt, melted butter and vanilla until combined.
Carefully add wet ingredients to dry, stirring with a wooden spoon until just combined. Take care to avoid overmixing.
Gently fold in fresh blueberries until evenly distributed.
Pipe batter into donut pan, filling cavities 3/4 of the way.
Bake for 13 minutes or until donuts turn golden brown and the tops spring back when pressed by a fingertip.
Cool donuts in pan for 5 minutes then remove to a wire rack to cool completely.
Clean donut pan, coat with nonstick spray then repeat the baking process with the remaining batter.
Donuts are best the day they are made but leftovers can be covered and stored at room temperature up to 2 days.