Preheat oven to 350° F. Spray two 6-cavity donut tins with nonstick spray and set aside.
In a large bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon and nutmeg.
In a medium bowl, whisk vigorously the granulated sugar, brown sugar and vegetable oil until well combined, about 1 minute. Add eggs and vanilla, and whisk again until incorporated, about 1 more minute. Add the flour mixture to the wet ingredients and mix just until combined. Fold in the shredded carrots with a spatula or wooden spoon.
Transfer the batter to a frosting bag or ziplock bag with a corner cut open. Fill each donut cavity about three-quarters full. Bake donuts at 350° F for 12 to 15 minutes, or until a toothpick inserted in the center comes out with little to no crumbs. Cool donuts in pan for 5 minutes, then transfer to a wire rack to cool completely.
For the cream cheese frosting, place cream cheese in a shallow bowl and heat in the microwave on 50% power level stopping to stir every 10 seconds until warm and thin enough to stir easily. Whisk in the confectioners’ sugar.
Dip the top of each donut in the glaze. Garnish with chopped pecans or walnuts.
Notes
Store carrot cake donuts in an airtight container at room temperature for 3 days or in the refrigerator for up to 5 days.Freeze carrot cake donuts for up to 1 month. Defrost in the refrigerator overnight.Recommended tools: kitchen scale, mixing bowls, box grater, donut pan