Preheat the oven to 350°F (175°C) and grease a donut pan.
In a mixing bowl, whisk together the flour, baking powder, baking soda, salt, and sugar.
In another bowl, whisk the melted butter, egg, milk, vanilla extract, and almond extract until combined.
Gradually add the wet ingredients to the dry ingredients, stirring until just combined.
Gently fold in the rainbow sprinkles to avoid color bleeding.
Spoon or pipe the batter into the donut pan, filling each cavity about 3/4 full.
Bake for 10-12 minutes, or until a toothpick inserted in the donuts comes out clean.
Allow the donuts to cool in the pan for 5 minutes, then transfer them to a cooling rack.
In a bowl, whisk together the powdered sugar, milk, and vanilla extract to make the glaze.
Dip the cooled donuts into the glaze and place them back on the cooling rack.
Immediately top with extra sprinkles before the glaze sets.
Let the glaze set for 10 minutes before serving.