FOR THE DONUTS:
Preheat the oven to 350 degrees F and spray a donut pan with non stick cooking spray.
In a large bowl, whisk together the four, sugar, baking powder and salt.
In a separate bowl, stir together the melted butter, egg, milk and vanilla extract.
Gradually add the wet ingredients into the dry ingredients until just combined (do not over mix).
Pour the mixture evenly into the donut pan filling each one about halfway full. I find that it’s easiest to use a piping bag to fill the donut pan or place the batter in a large ziplock bag and cut the corner off the bag to pipe the batter into the pan.
Then bake for 10-13 minutes until a toothpick inserted into the center of the donuts comes out clean. Let the donuts cool in the pan for 5 minutes and then transfer them to a wire rack to cool completely.
FOR THE TOPPINGS:
In a large bowl, beat together the butter until smooth.
Then add in the powdered sugar (1 cup at a time) on low speed until combined.
Then stir in the vanilla extract and the milk. Mix until the frosting is fluffy.
Place a layer of the frosting on the top of each donut.
Then start placing the mini M&Ms on the top half of the donuts into a rainbow shape. You will want to work fast to make sure the M&Ms are put on the donuts before the frosting is hard so that they stick into the frosting. Start with the red on the top outside of the donut, then the orange, yellow, green and blue.
Then place the remaining frosting in a piping bag and cut the tip off of the end of the bag. Dab the frosting at both ends of the M&Ms to make the clouds and make them look fluffy. Then place the white sprinkles on the clouds and enjoy!