Sweet rice flour , Bob's Red Mill
(see "Notes" below)
Instructions
Position racks in the upper and lower thirds of the oven and preheat to 350°F (180oC). Line 20 cups of 2 muffin tins with paper liners.
Pulse the erythritol and xylitol in a blender until finely ground. Set aside.
In a small saucepan, bring about 2 cups of water to a simmer over medium-low heat.
Place the chocolate and butter in a large heatproof bowl that can sit on top of the saucepan but not directly touching the water. Place the bowl on the pan and stir occasionally until the chocolate and butter are completely melted for about 10 minutes. Remove from the heat and set aside to cool slightly.
In a stand mixer with the paddle attachment, beat together 6 tablespoons of the powdered erythritol/xylitol mixture, the salt, and egg yolks on medium-high speed until the mixture is thick and pale, about 3 minutes.
Using a rubber spatula, gently fold the yolk mixture into the melted chocolate and stir in the vanilla powder, cocoa powder, and sweet rice flour.
In a separate bowl, with an electric mixer, beat the egg whites on medium speed until soft peaks form. Slowly beat in the erythritol/xylitol, then increase the speed to medium-high and beat until medium peaks form. (Be cautious of erythritol’s strongly cooling reaction with the proteins in the egg, which drops the temperature of the mixing bowl by about 20 degrees.)
Gently fold the egg white mixture into the chocolate mixture, one-third at a time, until combined.
Using a 1/4-cup ice cream scoop or cup measure, spoon the batter into the muffin cups. Bake until a toothpick inserted in the center of a cupcake comes out with a few moist crumbs, about 25 minutes. Let cool in the pan for about 5 minutes before transferring to a cooling rack to cool completely.
Notes:
If sweet rice flour is not available, just omit it; don’t substitute regular rice flour, which will make the cupcakes taste gritty.
