Preheat the oven to 450 degrees. Spray 2 (6 count) doughnut pans with cooking spray.

In a mixing bowl, whisk together the flour, cocoa powder, baking powder, baking soda and salt. In another mixing bowl, whisk together the sugar, eggs, oil, milk, and vanilla. Add the wet ingredients to the dry ingredients and whisk to combine. Spoon the batter into the doughnut pans, filling each form about ¾ full. Bake for 7-9 minutes or until the doughnuts spring back when lightly touched and a tooth pick inserted into a doughnut comes out clean. Let cool in the pan for 2-3 minutes, then transfer to a baking rack to finish cooling completely. Can be made a day or two ahead.

Using a mixer, beat the SunButter, powdered sugar, and milk together until smooth and creamy. Frost the cooled doughnuts.

Combine the seeds and nuts and sprinkle on top of the frosting. Can be made a day or two ahead. Store, covered, in the refrigerator.