Preheat oven to 350 degrees. Lightly spray donut pans with nonstick cooking spray. Set aside.
In a large bowl, combine flour, baking powder, baking soda and sugar.
1 cup all purpose flour, 1 teaspoon baking powder, 1/4 teaspoon baking soda, 1/4 cup granulated sugar
Melt butter in a small bowl. Add egg and milk. Stir well.
2 Tablespoons unsalted butter, 1 large egg, 1/2 cup + 2 Tbsp vanilla flavored milk
Add wet ingredients into dry ingredients and stir to combine. Divide batter between three bowls. To each bowl, add 1-2 drops of food coloring and stir. (I used one drop for each of my colors) Spoon into donut pan wells.
pastel food coloring
Bake donuts for 10 minutes in preheated oven. Remove from oven and let cool for 2 minutes in pan. Transfer to wire cooling racks and cool completely.
Frosting
In a medium bowl, mix powdered sugar, vanilla extract and 1 Tbsp water. Stir well. Divide into separate bowls and add 1 drop of food coloring to each. Stir well. Dip donuts into glaze and return to rack to set.
1 cup powdered sugar, 1 tsp vanilla extract, 1-2 Tablespoons water