Preheat oven to 325°F
Mix flour, baking powder and salt. Set aside.
Using hand mixer; combine butter and sugar.
Add egg, Greek yogurt, milk and vanilla. Mix.
Mix in dry ingredients until batter just comes together.
Spray donut pan with nonstick.
Fill donut molds with batter. I transfer batter to a sandwich bag, snip one bottom corner and pipe batter into molds.
Bake 12-14 minutes.
Transfer to cooling rack and allow to cool completely before glazing.