Preheat your oven to 350 degrees Fahrenheit. Prepare your cupcake pans by lining them with cupcake liners to prevent sticking. This step is crucial for a clean release when the cupcakes are done baking.
In a medium bowl, whisk together all-purpose flour, baking powder, and salt. This helps to ensure that the leavening agent is evenly distributed throughout the flour.
In a large mixing bowl, combine melted unsalted butter and granulated sugar using a hand mixer. Mix for about 30 seconds until the mixture becomes thick and yellow, indicating that the sugar is well incorporated.
Add the eggs one at a time, beating well after each addition. This helps to aerate the mixture, contributing to a light and fluffy cupcake.
Next, mix in vanilla. The aroma will be delightful and add depth to your cupcakes.
Now, alternate adding the dry flour mixture and buttermilk to the wet ingredients, starting and ending with the flour. This method helps to create a smooth batter without overmixing, which can lead to dense cupcakes.
Once the batter is ready, fill each cupcake liner about two-thirds full. This allows room for the cupcakes to rise without overflowing.
Place the filled pans into the preheated oven and bake for 15 to 20 minutes. Keep an eye on them; they’re done when a toothpick inserted comes out clean. This step is crucial for achieving that perfect bake.
Remove the cupcakes from the oven and allow them to cool completely before frosting. Frosting warm cupcakes can cause the frosting to melt and not hold its shape.
Once cooled, frost with your choice of Chocolate Buttercream, Vanilla Buttercream, or Cream Cheese Frosting. Top with additional rainbow sprinkles for a festive touch!