Step 1: Preheat your oven to 350°F (175°C) and line your cupcake pan with cupcake liners.
Step 2: In a large mixing bowl, whisk together the all-purpose flour, baking powder, and salt until well combined. Set aside.
Step 3: In another bowl, combine the melted butter and granulated sugar. Mix until well blended. Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract and buttermilk until smooth.
Step 4: Gradually add the dry ingredients to the wet mixture, stirring gently until just combined. Be careful not to overmix. Fold in the red, white, and blue sprinkles for that festive touch.
Step 5: Spoon the batter into the prepared cupcake liners, filling each about two-thirds full. Bake in the preheated oven for 18-20 minutes or until a toothpick inserted into the center comes out clean. Allow them to cool in the pan for a few minutes before transferring to a wire rack to cool completely.
Step 6: While the cupcakes are cooling, prepare the frosting. In a large mixing bowl, beat the softened butter until creamy. Gradually add the powdered sugar and mix until well combined. Stir in the salt and vanilla extract. Add the heavy whipping cream, one tablespoon at a time, until you reach your desired consistency.
Step 7: Once the cupcakes are completely cool, use a spatula or piping bag to frost each cupcake generously. Top with additional sprinkles for that extra festive flair!