Preheat the oven to 350 degrees. Gather all your ingredients. Prepare the mini muffin tin by placing mini cupcake liners.
In the bowl of a stand mixer, combine the softened butter and sugar. Cream until smooth.
Add in the egg, vanilla and milk and mix until combined.
Add in the flour, baking powder and salt. Mix until smooth - scraping the sides often and mixing well.
Use a small ice cream scoop or a tablespoon to divide out the batter and fill each of the mini cupcake liners until they are about ⅔ full.
Bake in the preheated oven for about 14-16 minutes or just until the edges are slightly brown and the center is set. Allow to cool completely before decorating.
For the frosting
In the bowl of a stand mixer, combine the softened butter, powdered sugar, vanilla, salt and milk.
Mix on low speed until combined. Then bump up the speed to medium and mix until smooth and fluffy. Stop the machine, scrape down the sides and mix again to ensure everything is thoroughly combined.
Transfer the frosting to a piping bag fitted with a large star tip.
Once the cupcakes are cool, pipe a mound of frosting on each cupcake. Decorate with sprinkles.
Storage: Cupcakes can be stored in an airtight container in the fridge for up to 3 days or frozen for 3 months.
I made mini cupcakes. For regular size, bake them for 18 to 22 minutes.