For the cupcakes
3/4 cup (105 g) all purpose gluten-free flour (I used Better Batter)
Scant 1/2 teaspoon xanthan gum (omit if your blend already contains it)
1 tablespoons (9 g) cornstarch
1/2 teaspoon baking powder
1/4 teaspoon baking soda
1/4 teaspoon kosher salt
4 tablespoons (56 g) unsalted butter, at room temperature
1/2 cup (100 g) granulated sugar
1 egg (50 g, weighed out of shell), at room temperature
1 teaspoon pure vanilla extract
1/3 cup buttermilk, at room temperature
1 1/2 tablespoons (15 g) gluten-free edible rainbow confetti sprinkles, plus more for topping the buttercream
For the vanilla buttercream frosting
8 tablespoons (112 g) unsalted butter, at room temperature
1 to 1 1/2 cups (115 to 175 g) confectioners’ sugar
1/8 teaspoon kosher salt
1/4 teaspoon pure vanilla extract (clear vanilla extract if you want a perfectly white frosting)
Milk by the teaspoonful, at room temperature
Preheat your oven to 350°F. Line 9 wells of a standard 12-cup muffin tin with cupcake liners or grease the wells, and set the tin aside. Depending upon the size of your muffin wells, you may only make 8 cupcakes.
In a small bowl, place the flour, xanthan gum, baking powder, baking soda, and salt, and whisk to combine well. Set the bowl aside. In the bowl of a stand mixer fitted with the paddle attachment or a large bowl with a hand mixer, beat the butter and sugar until light and fluffy. Add the egg and vanilla, and beat well. Add half of the flour mixture and beat just to combine. Add the buttermilk, and beat just to combine. Finally, add the remaining flour mixture, and beat until just combined. Add the edible confetti, and mix gently until the confetti pieces are evenly distributed throughout the batter.
Fill the prepared wells of the muffin tin about 2/3 of the way full with the batter. Shake the tin back and forth to help the batter settle into an even layer in each well. Place in the center of the preheated oven and bake until lightly golden brown and a tester comes out with no more than a few moist crumbs attached (about 19 minutes). Allow the cupcakes to cool for at least 5 minutes in the tin before transferring to a wire rack to cool completely.
To make the buttercream, place the butter in a large bowl with a hand mixer or the bowl of a stand mixer fitted with the paddle attachment, and beat on medium speed until creamy (about 30 seconds). Add 1 cup (115 g) of confectioners’ sugar, the salt, vanilla, and 1 teaspoonful of milk, and beat on medium speed until well-combined (about 1 minute). Beat in more confectioners’ sugar until the consistency is thick but not stiff. Turn up the mixer speed to high and beat for about 5 minutes or until light and fluffy. Transfer the frosting to a piping bag fitted with your favorite piping tip (in the photos here, I used a Wilton brand “2D” piping tip) to pipe the frosting on the cooled cupcakes, or use two spoons to scoop a generous amount onto each cupcake. Top with a few more pieces of edible confetti.
Originally published on the blog in 2013. All photos and video new. Cupcake recipe scaled down; buttercream recipe new.