Preheat oven to 350°F. Spray a donut pan well with non-stick cooking spray and set aside.
In a large mixing bowl, mix together the Bob's Red Mill Organic Unbleached All Purpose White Flour, baking powder, cinnamon, ginger, nutmeg, and salt. Set aside.
In a separate mixing bowl, mix together the buttermilk, oil, brown sugar, egg, and vanilla until fully combined.
Add the dry ingredients to the wet ingredients and mix until just combined. Add the grated carrots and gently mix them into the batter.
Spoon the batter into each cavity of the donut pan, making sure to only fill them 2/3 - 3/4 of the way full. You should get about 8 donuts, if you have a 6-count donut pan you will need to bake in separate batches.
Bake for about 10 minutes at 350°F or until a wooden toothpick inserted into the donut comes out clean. Remove from the oven and cool in the pan for about 5 minutes. Remove the donuts from the pan and transfer to a wire rack to finish cooling.
To make the cream cheese frosting:
In a mixing bowl, using an electric mixer, beat the cream cheese and butter until smooth. Add in the powdered sugar and vanilla and mix until fully combined.
Frost the cooled donuts as desired.
Prepared donuts are best eaten the same day, but can be stored in an airtight container in the refrigerator for up to two days.