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, granulated sugar, ground cinnamon, and ground nutmeg until well combined.
03 - In a separate medium bowl, whisk together eggs, whole milk, pumpkin puree, melted butter, and vanilla extract until smooth and uniform.
04 - Pour the wet ingredients into the dry ingredients. Stir gently with a spatula or wooden spoon until just combined; do not overmix as this can make the donuts tough.
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, or until the donuts are puffed and lightly golden. A toothpick inserted into the center should come out clean.
07 - Let cool in the pan for 5 minutes, then carefully turn out onto a wire rack to cool completely before glazing.
08 - In a small bowl, whisk together powdered sugar, pure maple syrup, and a pinch of salt. Add milk 1 teaspoon at a time, whisking until a thick but pourable glaze forms.
09 - Dip the tops of cooled donuts into the glaze, allowing excess to drip off. Place back on the wire rack and let stand until the glaze is set, about 15–20 minutes.