Gluten Free Tiramisu Cupcakes

FOR THE CUPCAKES 1 recipe Gluten Free Sponge Cake batter

FOR THE FROSTING 1 1/2 tablespoons (12 g) cornstarch

basic xanthan gum-free gluten-free flour blend (12 g superfine white rice flour + 4 g potato starch + 2 g tapioca flour/starch)

granulated sugar

(1/8 teaspoon) kosher salt

milk (any kind – just not nonfat)

pure vanilla extract

unsalted butter, at room temperature (it must be at room temperature)

mascarpone cheese, at room temperature

FOR THE SYRUP 1/2 cup + 2 tablespoons (5 fluid ounces) strong brewed coffee (or just use water)

granulated sugar

unsweetened cocoa powder (preferably Dutch-processed, if possible)

kosher salt

FOR SERVING Unsweetened cocoa powder, for dusting