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Black Widow Peanut Butter Bars

These Black Widow Peanut Butter Bars are a deliciously creamy peanut butter treat topped with rich chocolate frosting and spooky decorations. Perfect for any fun occasion!
Print Recipe Save it
Prep Time 20 minutes
Cook Time 30 minutes
Total Time 50 minutes
Course Dessert
Servings 12 servings

Equipment

  • Mixing Bowls
  • Whisk or electric mixer
  • 9x13 inch baking pan
  • Parchment Paper
  • Spatula
  • Measuring cups and spoons

Ingredients
  

For the Peanut Butter Base:

  • 1.5 sticks salted butter melted
  • 3/4 cup salted butter melted
  • 2 cups creamy peanut butter
  • 3/4 cup light brown sugar
  • 1/4 cup granulated sugar
  • 2 large eggs at room temperature
  • 1 tablespoon vanilla extract
  • 2 cups all-purpose flour
  • 1 teaspoon baking powder
  • 1/2 teaspoon kosher salt

For the Chocolate Frosting:

  • 1 stick salted butter room temperature
  • 1/2 cup salted butter room temperature
  • 2-3 cups powdered sugar
  • 1/2 cup cocoa powder
  • 2 teaspoons vanilla extract
  • 1/4 cup warmed milk

For Decorations:

  • Mini marshmallows
  • Whoppers
  • Candy eyes
  • Melted chocolate for drizzling
  • Black or silver sprinkles
  • Small plastic spiders optional

Instructions
 

Preparation

  • Preheat your oven to 350°F (175°C) to ensure even baking.
  • Line a 9x13 inch baking pan with parchment paper, leaving an overhang for easy removal.

Make the Peanut Butter Base

  • Melt 1 1/2 sticks (3/4 cup) of salted butter in a large mixing bowl.
  • Add 2 cups of creamy peanut butter, 3/4 cup light brown sugar, and 1/4 cup granulated sugar to the melted butter. Mix until smooth.
  • Add 2 large eggs, one at a time, mixing well after each addition.
  • Stir in 1 tablespoon vanilla extract until fully combined.
  • In a separate bowl, whisk together 2 cups all-purpose flour, 1 teaspoon baking powder, and 1/2 teaspoon kosher salt.
  • Gradually add the dry ingredients to the peanut butter mixture, stirring until just combined.
  • Spread the batter evenly in the prepared baking pan.
  • Bake for 25-30 minutes or until a toothpick inserted in the center comes out clean.
  • Allow the bars to cool completely in the pan on a wire rack.

Prepare the Chocolate Frosting

  • Cream together 1 stick (1/2 cup) room-temperature salted butter with 2-3 cups powdered sugar and 1/2 cup cocoa powder in a mixing bowl.
  • Add 2 teaspoons vanilla extract and 1/4 cup warmed milk. Beat until smooth and creamy.

Assemble and Decorate

  • Once the bars are completely cool, spread the chocolate frosting evenly over the top.
  • Top with mini marshmallows, Whoppers, candy eyes, drizzle melted chocolate, and sprinkle with black or silver sprinkles. Optionally add small plastic spiders for a Halloween theme.
  • Lift the bars out of the pan using the parchment paper overhang and slice into squares. Serve and enjoy!

Notes

  • Store bars in an airtight container at room temperature for up to 3 days or refrigerate up to a week.
  • Freeze wrapped bars for up to 3 months; thaw before serving.
  • For gluten-free bars, substitute all-purpose flour with a gluten-free flour blend containing xanthan gum.
  • Use natural peanut butter for a less sweet, thicker texture but adjust sugar accordingly.
  • Customize decorations seasonally, like orange and black sprinkles for Halloween or crushed peppermint for Christmas.
Keyword Chocolate, Easy, Halloween, Peanut Butter, Quick