Preheat your oven to 350°F and line a muffin pan with liners or lightly grease it with gluten-free nonstick cooking spray.
In a large mixing bowl, cream the softened butter until smooth. Add the sugar and beat until fully blended.
Incorporate the eggs and vanilla extract, mixing until the batter is smooth and combined.
Add the gluten-free flour, baking powder, and salt. Mix until just combined.
Slowly pour the milk into the mixture. Beat on medium speed for about two minutes, creating a smooth batter.
Using a greased ice cream scoop, evenly divide the batter into the prepared muffin pan.
Bake for 25 minutes, or until a toothpick inserted into the center comes out clean. Check on them earlier if your oven runs hot.
Let the cupcakes cool completely on a wire rack before frosting.
To make the frosting, cream the butter until smooth. Blend in the vanilla extract and salt.
Add the confectioners’ sugar one cup at a time, mixing thoroughly after each addition.
Add milk in small increments until the frosting reaches your desired consistency.