• Preheat the oven to 350°F.
• In a mixing bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt until the mixture is well combined.
• In a separate mixing bowl, beat the softened butter and granulated sugar with an electric mixer until the mixture is light and fluffy.
• Beat in the eggs one at a time, mixing well after each addition.
• Add the milk and vanilla extract to the mixture and mix well.
• Gradually add the flour mixture to the butter mixture, mixing well after each addition.
• Line a cupcake pan with cupcake liners.
• Spoon the batter into the cupcake liners, filling each about 2/3 full.
• Bake the cupcakes in the preheated oven for 18-20 minutes or until a toothpick inserted into the center of a cupcake comes out clean.
• Let the cupcakes cool completely before frosting.

For the frosting:

• Beat the softened butter with an electric mixer until the mixture is light and fluffy.
• Gradually add the powdered sugar to the butter, mixing well after each addition.
• Add the milk and vanilla extract to the mixture and mix well.
• Beat the mixture until it is light and fluffy.
• Spoon the frosting into a piping bag and pipe the frosting onto the cooled cupcakes.
• Decorate the cupcakes with sprinkles or other toppings of your choice.