Small Batch Vanilla Cupcakes

Name: Small Batch Vanilla Cupcakes
Prep time: 10 min
Cook time: 15 min
Total time: 25 min
Cuisine: American
Ingredients: 1/2 cup all purpose flour (see note); 1/2 teaspoon baking powder; 1/8 teaspoon salt; 1 large egg; 1/4 cup granulated sugar; 2 teaspoons pure vanilla extract; 4 tablespoons unsalted butter (melted and slightly cooled); 1/4 cup milk (preferably whole or 2% milk); 3/4 cup powdered sugar; 3 tablespoons unsalted butter (at room temperature); 1/4 teaspoon pure vanilla extract; 1-2 teaspoons milk (I used whole milk)