Mochi Doughnuts

Whisk 1 cup plus 1 Tbsp. (170 g) mochiko (sweet rice flour) and 1 cup (120 g) tapioca starch (tapioca flour) in a small bowl to combine.

Bring ⅔ cup whole milk, ⅓ cup (67 g) granulated sugar, 2 Tbsp. unsalted butter, and ½ tsp. Diamond Crystal or ¼ tsp. Morton kosher salt to a boil in a medium saucepan over medium-high. Remove from heat, add dry ingredients, and stir with a wooden until a lumpy paste forms. (Mixture will be dry in spots and hard to combine, but don’t worry; this is normal.)

Transfer dough to the bowl of a stand mixer fitted with the paddle attachment and mix on medium speed to release some steam and cool slightly, until smooth, about 2 minutes. Add 1 large egg and mix (still on medium speed) until combined, about 2 minutes. Add 2 tsp. baking powder and mix until combined and dough is sticky but smooth, about 30 seconds. Place a piece of plastic directly on top of dough and let rest 15 minutes.