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 well combined.
03 - In a separate bowl, whisk together eggs, milk, pumpkin puree, melted butter, and vanilla extract until smooth and creamy.
04 - Pour the wet ingredients into the dry ingredients. Stir gently until just combined; do not overmix to maintain tender texture.
05 - Transfer batter to a piping bag or large zip-top bag with a corner snipped off. Pipe batter evenly into donut pan cavities, filling each about 3/4 full.
06 - Bake for 20-25 minutes until donuts are puffed and lightly golden. Cool in pan for 5 minutes, then turn out onto wire rack to cool completely.
07 - Whisk together powdered sugar, maple syrup, and pinch of salt. Add milk 1 teaspoon at a time until thick but pourable consistency forms.
08 - Dip tops of cooled donuts into glaze, allowing excess to drip off. Return to wire rack and let glaze set completely before serving.