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Peanut Butter Lava Fudge Cupcakes

These Peanut Butter Lava Fudge Cupcakes are pure indulgence — soft chocolate cupcakes filled with warm molten fudge and topped with creamy peanut butter frosting. Each bite is rich, gooey, and perfectly balanced between salty and sweet. A must-bake dessert for peanut butter lovers everywhere!
Print Recipe
Prep Time 35 minutes
Cook Time 25 minutes
45 minutes
Total Time 1 hour 45 minutes
Servings 16

Ingredients
  

For the Hot Fudge Sauce

  • 5 oz semisweet chocolate finely chopped
  • 2 tbsp + 2 tsp cocoa powder
  • 6 tbsp light corn syrup
  • 2 tbsp + 2 tsp sugar
  • 3 tbsp heavy cream
  • 3 tbsp milk or water for darker chocolate flavor
  • Pinch of salt
  • 1 ½ tbsp unsalted butter
  • ½ tsp vanilla extract optional

For the Cupcakes

  • ½ cup unsalted butter softened
  • 1 ½ cups light brown sugar packed
  • 2 large eggs room temperature
  • 1 ½ tsp vanilla extract
  • ½ cup unsweetened cocoa powder
  • 1 ½ tsp baking soda
  • ¼ tsp salt
  • 1 ½ cups cake flour
  • ⅔ cup sour cream
  • ¾ cup hot water or coffee

For the Peanut Butter Frosting

  • 1 ¼ cups unsalted butter softened
  • 1 ⅓ cups creamy peanut butter
  • 3 tbsp heavy cream
  • 2 ½ tsp vanilla extract
  • Pinch of salt
  • 2 ¼ cups powdered sugar

For Garnish (Optional)

  • Chocolate-covered pretzels
  • Crushed peanuts or chocolate sprinkles
  • Melted chocolate for sticking garnish

Instructions
 

Prepare the Fudge

  • Combine chocolate, cocoa, corn syrup, sugar, cream, milk, and salt in a saucepan.
  • Cook over medium heat, whisking constantly until melted and smooth.
  • Remove from heat, stir in butter and vanilla.
  • Let cool until thick but pourable.

Make the Cupcakes

  • Preheat oven to 350°F (175°C) and line muffin tin with liners.
  • Cream butter and brown sugar until fluffy. Add eggs and vanilla.
  • In another bowl, mix cocoa, baking soda, salt, and flour.
  • Alternate adding dry ingredients and sour cream to the butter mixture.
  • Slowly mix in hot water or coffee until batter is smooth.
  • Fill liners halfway, spoon a teaspoon of fudge into each, then cover with more batter.
  • Bake 22–25 minutes or until set. Cool completely.

Make the Frosting

  • Beat butter and peanut butter until creamy.
  • Add sugar, cream, vanilla, and salt.
  • Beat until fluffy and smooth.

Assemble

  • Frost cooled cupcakes, garnish with pretzels or crushed peanuts, and drizzle with extra fudge if desired.

Notes

  • Use dark chocolate for a deeper fudge flavor.
  • Serve slightly warm to enhance the lava effect.
  • Store leftovers in the fridge for up to 3 days.