01 - Preheat oven to 350°F. Lightly grease a standard donut pan with cooking spray or butter.
02 - In a large mixing bowl, whisk together sweet rice flour, granulated sugar, baking powder, and sea salt until evenly distributed.
03 - In a separate bowl, beat eggs thoroughly. Whisk in milk, melted butter, lemon juice, lemon zest, and vanilla extract until fully incorporated.
04 - Pour the wet mixture into the dry ingredients. Stir gently until just combined and smooth, being careful not to overmix.
05 - Transfer batter to a piping bag or zip-top bag with corner snipped. Pipe batter into prepared donut cavities, filling each about 3/4 full.
06 - Bake for 18-20 minutes until donuts are puffed and lightly golden. A toothpick inserted into the center should come out clean.
07 - Let donuts rest in pan for 5 minutes to set, then carefully transfer to a wire rack to cool completely before glazing.
08 - In a small bowl, whisk together powdered sugar, lemon juice, and lemon zest until smooth and pourable. Add more lemon juice if needed for desired consistency.
09 - Dip tops of cooled donuts into the glaze, allowing excess to drip off. Return to wire rack and let glaze set for 15-20 minutes before serving.