01 - Preheat oven to 350°F. Lightly grease a 12-cavity donut pan with cooking spray or butter.
02 - In a large bowl, whisk together sweet rice flour, tapioca starch, baking powder, salt, sugar, cinnamon, and nutmeg until fully blended.
03 - In a separate bowl, whisk together eggs, milk, pumpkin puree, melted butter, and vanilla extract until smooth and emulsified.
04 - Pour the wet ingredients into the dry ingredients. Stir gently until just combined; be careful not to overmix as this can affect the texture.
05 - Transfer the batter to a piping bag or large zip-top bag with a corner snipped off. Pipe batter evenly into the donut pan cavities, filling each about 3/4 full.
06 - Bake for 20-25 minutes, until the donuts are puffed and lightly golden on top. Allow to cool in the pan for 5 minutes before transferring.
07 - Whisk together powdered sugar, maple syrup, and a pinch of salt. Add milk, 1 teaspoon at a time, until a thick but pourable glaze consistency is achieved.
08 - Dip the tops of completely cooled donuts into the glaze, allowing excess to drip off. Place back on the wire rack until the glaze sets, approximately 15-20 minutes.