Preheat the oven to 350° and grease donut pans with cooking spray.
In a large bowl whisk together flour, sugar, baking powder, and salt.
In a medium bowl whisk together the butter, eggs, milk and vanilla.
Add the wet ingredients to the dry ingredients and mix together until smooth.
Use a large ziplock bag with the corner snipped off or a large pastry bag to pipe the batter into the greased donut pans, filling the pans only ¾ of the way full.
Bake for 10-12 minutes, until golden brown. While the donuts are baking, mix together the vanilla glaze.
Cool for 5-10 minutes before dipping in the glaze and sprinkling with desired sprinkles. Cool completely on a cooling rack.
Mix the powdered sugar, melted butter and vanilla. Add the milk 1 tbsp at a time until it reaches the desired thickness. You don't want it to be so thin that it runs right off the donut, but you also don't want it to be thick and paste like.