Monster Mud Bars Recipe: No-Bake Peanut Butter Marshmallow Halloween Bars

Nutter Butter Crust

• 24 Nutter Butter cookies, about 11 ounces
• 5 tablespoons unsalted butter, melted
• Pinch of salt

Peanut Butter Cream Cheese Layer

• 8 ounces cream cheese, softened
• ¾ cup creamy peanut butter
• ¾ cup powdered sugar
• 1 teaspoon vanilla extract
• Pinch of salt
• ½ cup whipped topping or softly whipped heavy cream

Marshmallow Layer

• 2 cups mini marshmallows
• ½ cup marshmallow creme
• 2 tablespoons creamy peanut butter

Chocolate Peanut Butter Topping

• 1½ cups semisweet chocolate chips
• ½ cup heavy cream
• 2 tablespoons creamy peanut butter

Halloween Toppings

• About ¼ cup Reese’s Pieces, roughly crushed
• Mini marshmallows
• Candy eyes
• Crushed Nutter Butter cookies, optional
• Halloween sprinkles, optional
• Flaky salt, optional

Make it weird

Candy Eyes

The easiest way to turn every square into a different little monster. Press them into the chocolate while it is still soft so they stay put.

SHOP CANDY EYES

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1. Make the Nutter Butter crust

Line an 8 × 8-inch pan with parchment paper, leaving enough hanging over the sides to lift the bars out later.

Crush the Nutter Butter cookies into fine crumbs. Mix with the melted butter and a pinch of salt. Press the mixture firmly and evenly into the bottom of the pan. Refrigerate for 20 to 30 minutes while you make the filling.

2. Make the peanut butter cream cheese layer

Beat the softened cream cheese and peanut butter together until completely smooth. Add the powdered sugar, vanilla, and salt and continue beating until light and creamy.

Fold in the whipped topping or whipped cream, then spread the mixture evenly over the chilled crust.

3. Add the marshmallow layer

Scatter the mini marshmallows over the peanut butter filling.

Stir the marshmallow creme together with 2 tablespoons peanut butter. Dollop it across the marshmallows and gently spread it around. It does not need to look perfect. The swirls and gooey pockets are part of the point.

4. Make the chocolate topping

Place the chocolate chips in a heatproof bowl. Heat the heavy cream just until steaming, then pour it over the chocolate. Let it sit for 2 minutes.

Stir until completely smooth and glossy, then stir in the peanut butter. Pour the chocolate over the marshmallow layer and gently spread it to the edges.

5. Make it Halloween

While the chocolate is still soft, sprinkle the top with roughly crushed Reese’s Pieces. Keep the pieces chunky so you get visible bits of orange, yellow, and brown candy instead of candy dust.

Add mini marshmallows and candy eyes wherever you like. Finish with Nutter Butter crumbs, Halloween sprinkles, or a tiny pinch of flaky salt if you want more texture.

6. Chill

Refrigerate for at least 3 hours, or until completely firm. Chilling overnight works even better if you want especially clean slices.

7. Slice and serve

Lift the chilled dessert out of the pan using the parchment paper. Cut into 16 squares with a sharp knife. Wipe the knife clean between cuts if you want neat layers.

Let the bars sit at room temperature for about 10 minutes before eating so the peanut butter layer softens slightly and the marshmallow gets extra gooey.

Make Them Extra Monstrous

Instead of decorating every square separately, decorate the whole pan before chilling. Cluster the eyes in strange little groups, build crooked teeth from mini marshmallows, and scatter the Reese’s Pieces unevenly across the chocolate.

Once you slice through it, every bar becomes its own slightly different monster.

Storage

Keep the bars covered in the refrigerator for up to 5 days. Because of the cream cheese filling, keep them refrigerated until shortly before serving.

Snaxtime Tip

These are rich, so smaller squares work surprisingly well on a Halloween dessert table. Put them out with popcorn, candy corn, gummy worms, and salty snacks and let everyone destroy the tray themselves.