Preheat your oven to 375°F (190°C). Grease a donut pan.
In a mixing bowl, whisk together the flour, sugar, baking powder, and salt.
In another bowl, combine the milk, eggs, melted butter, and vanilla extract.
Pour the wet ingredients into the dry ingredients and mix until just combined.
Fill the donut pan about ¾ full with the batter.
Bake for 12-15 minutes, or until the donuts are golden brown.
Let the donuts cool in the pan for a few minutes, then transfer to a wire rack to cool completely.
For the topping, mix the powdered sugar and milk to make a glaze. Dip the cooled donuts into the glaze, then into the sprinkles.