Preheat oven to 350°F. Grease a donut pan with oil or butter; set aside.
Make the donuts: In a large bowl, whisk together flour, brown sugar, baking powder, cinnamon, cloves, nutmeg, and salt. Set aside.
In a separate bowl, whisk the egg, milk, melted butter, and vanilla. Stir the wet mixture into the dry ingredients until just combined. Spoon or pour the batter into the donut pan, filling each one a little more than 3/4 full.
Bake for 12-15 minutes or until a toothpick inserted into the center of the donuts comes out clean. Let the donuts cool in the pan for 5 minutes before transferring to them to a wire rack to cool.
Make the glaze: Combine the powdered sugar, milk, and maple syrup in a bowl. Stir and add additional powdered sugar or milk to reach desired consistency. I like the glaze to be liquid enough to dunk the donuts in but thick enough that it sits up slightly. The glaze continues to thicken as it sits too.
Once the donuts are cool (this only takes a few minutes), dip the tops of the donuts into the maple glaze and immediately sprinkle with chopped pecans.
Notes
To Store:
The donuts are best on the day they are made. If you have any leftovers, store in the refrigerator for up to 3 days.