Step 1

Preheat the oven to 350°F. Line a with cupcake liners.

Step 2

In a large mixing bowl, combine the sugar, vegetable oil, eggs and vanilla extract. Beat on medium speed until the eggs and oil are well incorporated and the batter is lighter in color, about 2 minutes. Scrape down the bowl as needed. Next mix in the sour cream and beat until well combined.

Step 3

Combine the dry ingredients in a separate bowl. Alternate adding half the dry ingredients followed by the half the milk and mix just until the flour starts to incorporate. Use a spatula to scrape down the sides of the bowl and stir the batter from the bottom to the top to ensure it’s well mixed.

Step 4

Using a large cookie scoop, divide the batter evenly, filling each liner 2/3 full. Careful not to overfill. Bake at 350°F for 14-16 minutes. Test the cupcakes for doneness by inserting a toothpick into the center of the cupcake. If the toothpick comes out clean, the cupcakes are done. Cool Completely.

Step 5

Cut the butter into pieces. Using the paddle attachment, whip the butter at medium high speed for 3-4 minutes, scraping down the bowl occasionally. Beat the butter until it looks lighter in color.

Step 6

Next add the peanut butter and incorporate into the butter, scraping the bowl as needed.

Step 7

Slowly add the powdered sugar, 2 cups at a time, adding the heavy cream and vanilla intermittently, mixing on low speed until it’s incorporated into the butter. Then increase the speed to high and beat for 30-60 seconds. Repeat until all your powdered sugar has been added.

Step 8

Lastly, add the marshmallow crème and beat until it’s well incorporated. Use a large piping bag fitted with a large open round piping tip to decorate these cupcakes.

Step 9

Use a cupcake cupcake corer and take the top half of the center of your cupcakes out.

Step 10

Fill your piping bag with marshmallow crème and use the piping bag to fill the centers of the cupcakes.

Step 11

Pull the tops off those center pieces you previously removed and plop it back on top of the marshmallow filling.

Step 12

Chop the peanuts into small pieces. Hold the cupcake in one hand and fill your other hand with peanuts. Gently press the peanuts into sides of the frosting. Store in an airtight container.