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Peanut butter chocolate cupcakes on a platter.

Peanut Butter Chocolate Cupcakes

Stephanie Rutherford
These fluffy peanut butter chocolate cupcakes are moist dark chocolate cupcakes filled with peanut butter marshmallow fluff. They are topped with peanut butter frosting.
5 from 10 votes
Prep Time 1 hr
Cook Time 18 mins
Chilling Time 15 mins
Total Time 1 hr 33 mins
Course Dessert
Cuisine American
Servings 12 Cupcakes
Calories 511 kcal


Chocolate Cupcakes

  • 1 cup All-purpose flour
  • ½ cup Unsweetened cocoa powder
  • ¼ teaspoon Baking soda
  • 1 teaspoon Baking powder
  • ¾ cup White granulated sugar
  • ¼ cup Brown sugar packed light or dark
  • ¼ teaspoon Salt
  • cup Oil canola or vegetable
  • 2 Large eggs room temperature
  • 2 teaspoon Pure vanilla extract
  • ½ cup Buttermilk room temperature
  • ½ cup Hot water steaming

Peanut Butter Marshmallow Filling

  • cup Peanut Butter smooth
  • cup Marshmallow fluff
  • 2 tablespoon Milk
  • ½ teaspoon Ground cinnamon
  • 1 ½ tablespoon Powdered Sugar

Peanut Butter Buttercream

  • 1 cup Unsalted butter slightly cold
  • 1 cup Peanut butter creamy
  • 3 cups Sifted powdered sugar
  • 2 teaspoon Pure vanilla extract
  • ¼ cup Heavy whipping cream cold
  • Reese's peanut butter cups for decoration


Chocolate Cupcakes

  • Preheat oven to 350F and line a 12 cup muffin pan with muffin liners.
  • In a small bowl, sift together flour, cocoa powder, baking soda, baking powder, sugar, brown sugar, and salt. Set aside.
  • In a separate bowl, mix the oil, vanilla, eggs, and buttermilk together. Pour into the dry ingredients. Whisk until combined. Heat hot water on stove until steaming. Pour VERY slowly into batter. Pour a little and whisk until combined to avoid over cooking the eggs.
  • Use a 3 oz cookie scoop to scoop batter into pan. It should be ⅔rds full. Bake for 16-20 minutes. The cupcakes are done baking when a toothpick inserted comes out clean.
  • Let cupcakes sit in the pan for 10 minutes. Then, transfer to a cooling rack. Allow cupcakes to cool completely.

Peanut Butter Marshmallow Filling

  • In a medium bowl, combine peanut butter, marshmallow fluff, milk, and cinnamon. Once fully combined, slowly add in powdered sugar. It should be easily pipeable. Place in a piping bag.
  • Use a cupcake corer or a sharp knife to cut a hole ⅔rds down the cupcakes. Save the tops. Fill all the way with filling. Place tops back on.

Peanut Butter Buttercream.

  • Place butter on counter for 30 minutes for it to get slightly cold. Sift powdered sugar while you wait.
  • Use a mixer, and beat butter until fluffy. Scrape bowl and add in peanut butter. Beat for 2 minutes. Scrape the bowl several times to make sure butter is fully combined. It should be creamy.
  • Slowly add in powdered sugar and mix until combined. It will get very thick. Add in vanilla and heavy cream. Mix on low until combined. Then, beat on high for 3 minutes until fluffy. Cool in fridge for 15 minutes.
  • Pipe the frosting on top of the cupcakes. Top with Reese's peanut butter cups.


Flour- Make sure flour is spooned and leveled or use a kitchen scale. Compacted flour will dry out the cupcakes.
High altitude baking- Add an extra tablespoon of flour.


Calories: 511kcalCarbohydrates: 38gProtein: 10gFat: 39gSaturated Fat: 15gTrans Fat: 1gCholesterol: 49mgSodium: 256mgPotassium: 286mgFiber: 3gSugar: 23gVitamin A: 566IUVitamin C: 1mgCalcium: 65mgIron: 2mg
Keyword Chocolate cupcakes, dark chocolate, filled cupcakes, moist cake, Peanut butter frosting, peanut butter marshmallow creme, Reese's peanut butter cups
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