Preheat the oven to 350 degrees and add paper liners to the cupcake tin.
Cream together 12 tablespoons of butter and 1.5 cups of butter with a mixer. This takes 2 - 3 minutes.
Add in 3 teaspoons of vanilla, 4 eggs and 4 tablespoons of oil. Mix on medium speed until well combined.
Add in 1.25 cups of milk and mix on medium low until well combined. May appear curdles, this is normal.
Add in 2.5 cups flour, 2.5 teaspoons baking powder and .5 teaspoon of salt. Mix on low scraping down sides as needed until well combined.
Use a scoop or measuring cup to fill cupcake tin with batter. Each hole should be filled about ¾ of the way full.
Bake at 350 degrees for 14 - 16 minutes. Edges should be light brown and center should be set.
Make the frosting by adding 1 cup of butter and half of the powdered sugar, 1 teaspoon of salt and 1 teaspoon of vanilla into a mixing bowl. Mix on low until well combined.
Add in other half of powdered sugar and 2 - 3 tablespoons of milk. Mix on low until well combined and then bump speed to medium and mix for 2 more minutes. It should be thick and fluffy.
Divide the frosting equally into four bowls. In one add red food coloring, one add green food coloring, one add yellow food coloring and leave the last white.
Transfer frostings to piping bags with large piping tips.
Unwrap Reese's and place them in a ziploc bag with gold luster dust. Shake until candies are coated.
Pipe a large dollop of frosting on each cupcake. Then add color corresponding sprinkles to each cupcake.
Finally, pipe a small dollop of frosting on the top of bottom of each Reeses and place one on the top of each cupcake.