Preheat oven to 350°F. Line two (24 cavities total) muffin pans with paper liners or grease lightly with non-stick cooking spray. In bowl of stand mixer fitted with paddle attachment, combine granulated sugar, white rice flour, sweet rice flour, potato starch, baking powder, salt, and xanthan gum. Stir to combine.

Add shortening. Turn mixer on to medium-low speed. Mix until no large piece of shortening remain. Turn off mixer. Add water, vegetable oil, eggs, vanilla extract, and almond extract. Turn mixer on to medium-high. Mix for two minutes. (Timing is important with this batter.) Batter should be light and fluffy. Turn off mixer. If making a funfetti cake, add sprinkles. Turn mixer on to low and stir until sprinkles are just combined. Over-mixing causes the sprinkles to break up in the batter.

Fill each muffin cup about 2/3 full. Bake until a cake tester inserted into the center of a cupcake comes out clean, about 20 minutes. Cupcake tops should be golden brown. Allow cupcakes to cool in the pan for three minutes and then transfer to a wire rack to cool completely. Once cool, ice as desired.