Gluten Free Chocolate Cupcakes

Preheat the oven to 350°F. Line a muffin tin with cupcake liners.
In a small bowl, whisk together the gluten-free all-purpose flour, cornstarch, cocoa powder, baking powder, and salt. Set aside.
Place the sugar and butter in the bowl of a stand mixer fitted with the paddle attachment, and cream on high speed until light and fluffy, scraping down the bowl as needed, about 3–4 minutes.
Add the eggs one at a time, mixing until well combined after each addition. Mix in the vanilla extract.
Beginning and ending with the flour mixture, add ⅓ of the flour mixture and mix until just combined. Add ½ of the milk and mix until just combined. Repeat with another ⅓ of the flour mixture and the remaining milk. Finally, add the remaining flour mixture and mix until just combined, scraping down the bowl as needed.
Divide the batter evenly among the muffin cups. Let rest for 10 to 15 minutes.
Place the cupcakes in the oven and bake for 15–18 minutes, or until they spring back when gently pressed in the center. (You can also insert a toothpick into the center; if it comes out clean, they’re done.)
Let the cupcakes cool in the pan for 3–4 minutes. Remove from the pan and place on a cooling rack to cool completely.
Once the cupcakes are cool, frost as desired.