Preheat oven to 350 degrees F
Spray your donut pans with a non-stick spray.
In a large mixing bowl, whisk together the flour, baking powder, and salt.
Set to the side.
In a separate mixing bowl, mix together the milk, sugar, egg, oil, butter, lemon juice, lemon zest, and vanilla until fully combined.
Add your dry ingredients to the wet ingredients
Mix until combined.
Add your blueberries and lightly stir to combine.
Spoon batter into donut pan
Bake for 9-10 minutes until a toothpick inserted comes out clean.
Let cool 10 minutes.