Mix flours, sugar, salt, pumpkin pie spice, baking powder in a bowl. Set aside.
Whisk together milk and vinegar. Let sit for 5 minutes. Whisk in egg and vanilla, maple syrup, then melted (and cooled) butter.
Pour wet ingredients into dry and stir until no flour streaks are left.
Grease a 6 count donut pan, then spoon in batter. It will be thicker than normal batter. Level off with a spoon.
Bake for 11 minutes at 350 degrees, or until a toothpick comes out clean.
Remove each from pan once cooled. Running a knife around the edges is helpful to get them out gently.
Brush melted butter onto donut, then dip into the sugar mixed with cinnamon.