Preheat the oven to 350°F. Spray two donut pans with baking non-stick spray.
In a large bowl, mix the flour, baking powder, baking soda, and salt. Set aside.
2 cups All-purpose flour, 2 tsp Baking powder, 1/2 tsp Baking soda, 1 tsp Salt, Pinch of Nutmeg
In a separate bowl, mix the sugar, eggs, milk, sour cream, melted butter, and vanilla.
2/3 cup White granulated sugar, 2 Large eggs, 1/2 cups Milk, 1/2 cup Sour cream, 4 TBSP Unsalted butter, 1 tsp Pure vanilla extract
Pour the wet ingredients into the dry and mix until just combined.
Pour the batter into a piping bag (or ziplock bag) and pipe the batter into the donut pan. it should be 2/3rds full of batter. See picture in blog post.
Bake for 10-13 minutes until a toothpick inserted comes out clean. Let the donuts sit in the pan for 5 minutes before transferring to a cooling rack.