01 - Preheat oven to 350°F and 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, granulated sugar, cinnamon, and nutmeg until evenly distributed.
03 - In a separate bowl, whisk eggs, milk, pumpkin puree, melted butter, and vanilla extract until completely smooth and emulsified.
04 - Pour wet ingredients into dry ingredients. Fold gently until just combined, being careful not to overmix as this can make donuts tough.
05 - Transfer batter to a piping bag or large zip-top bag with corner snipped off. Pipe batter evenly into donut cavities, filling each about 3/4 full.
06 - Bake for 20-25 minutes until donuts are puffed, set, and lightly golden on top. Allow to cool in pan for 5 minutes.
07 - While donuts cool, whisk powdered sugar, maple syrup, and pinch of salt. Add milk 1 teaspoon at a time until thick but pourable consistency forms.
08 - Turn donuts onto wire rack and cool completely. Dip tops into glaze, allow excess to drip off, then return to rack until glaze sets.