Name: Slow Cooker Chocolate Peanut Butter Bars recipe
Prep time: 10 min
Cook time: 2 h
Total time: 4 h 10 min
Yield: 24
Cuisine: American
Ingredients: 1 box (15.25 oz) yellow cake mix; 10 tablespoons unsalted butter, melted and divided (8 Tbsp for base + 2 Tbsp for topping); 1 cup creamy peanut butter; 2 large eggs; 1 can (14 oz) sweetened condensed milk; 2 cups semi-sweet chocolate chips (or mixture of semi-sweet and milk chocolate)

Indulgent, fudgy bars featuring layers of gooey peanut butter and rich chocolate melted slowly in your crockpot. This effortless dessert combines creamy peanut butter with melty chocolate chips and a cake mix base for chewy, crowd-pleasing treats that set beautifully—no oven needed. Perfect for potlucks or sweet cravings.

Why You’ll Love This recipe

You’ll absolutely adore these Slow Cooker Chocolate Peanut Butter Bars because they deliver the ultimate peanut butter and chocolate combination with almost zero effort. The slow cooker does all the heavy lifting, gently melting everything together into a luscious, fudgy texture that’s impossible to achieve with traditional baking.

There’s no need to stand over a hot oven or worry about precise timing—the crockpot creates that perfect gooey center while the edges get slightly chewy for the best of both worlds. The recipe uses simple pantry staples, making it budget-friendly and accessible even on busy weeknights.

Kids and adults go crazy for the classic Reese’s-like flavor profile, and the bars slice cleanly once chilled, making them ideal for sharing at parties, gifting during holidays, or satisfying late-night sweet tooth attacks. Cleanup is a breeze too—just one pot and a lined pan!

Yield: 24 bars

Slow Cooker Chocolate Peanut Butter Bars recipe

Easy slow cooker fudgy peanut butter chocolate bars with gooey layers and rich flavor—no oven required!

Prep Time 10 minutes

Cook Time 2 hours

Additional Time 2 hours

Total Time 4 hours 10 minutes

Ingredients

1 box (15.25 oz) yellow cake mix
10 tablespoons unsalted butter, melted and divided (8 Tbsp for base + 2 Tbsp for topping)
1 cup creamy peanut butter
2 large eggs
1 can (14 oz) sweetened condensed milk
2 cups semi-sweet chocolate chips (or mixture of semi-sweet and milk chocolate)

Instructions

Grab your slow cooker and lightly spray the insert with non-stick cooking spray or line it with a slow cooker liner for super easy cleanup later—trust me, you’ll thank yourself!
In a large mixing bowl, combine the yellow cake mix, 8 tablespoons of melted butter, creamy peanut butter, and both eggs. Stir everything together with a sturdy spoon or spatula until a thick, cookie-dough-like mixture forms—don’t worry if it looks a little crumbly at first; it comes together beautifully.
Press about two-thirds of this peanut buttery base mixture evenly into the bottom of your prepared slow cooker, creating a nice flat layer that will become your chewy foundation.
Pour the entire can of sweetened condensed milk over the base layer and gently spread it out with the back of a spoon so it covers everything—this is what makes these bars extra gooey and dreamy!
Sprinkle 1½ cups of the chocolate chips evenly across the sweetened condensed milk layer. They’ll melt into pure chocolate magic during cooking.
Crumble the remaining peanut butter base mixture over the top like a delicious streusel—this creates those irresistible pockets of peanut butter throughout.
Drizzle the remaining 2 tablespoons of melted butter over the top, then finish by scattering the last ½ cup of chocolate chips for that gorgeous melty finish.
Pop the lid on your slow cooker, set it to LOW, and let it work its slow-cooker sorcery for 2 hours. Resist peeking too often, but give it a gentle stir around the 1-hour mark if you can.
When the edges look set and the top is bubbly and melty, turn off the slow cooker and carefully remove the insert (use oven mitts!). Let it cool in the insert for about 30 minutes—it’ll firm up as it cools.
Lift the whole batch out using the liner or parchment overhang, transfer to a cutting board, and chill in the fridge for at least 2 hours. Slice into squares with a sharp knife, then watch everyone fight over the last piece!

Notes

These bars are best served slightly chilled for the perfect fudgy texture, but they soften nicely at room temperature. If your slow cooker runs hot, check at 1 hour 45 minutes to avoid overcooking.

Nutrition Information

Yield

Serving Size

1
Amount Per Serving Calories 293Total Fat 17gSaturated Fat 8gUnsaturated Fat 9gCholesterol 29mgSodium 221mgCarbohydrates 35gFiber 2gSugar 22gProtein 5g

The recipes and nutritional information on Crock Pot Meal are for informational purposes only. Always consult a healthcare provider for personalized dietary advice.

Recipe Tips and Tricks

Use a 6-quart or larger slow cooker for even melting and to avoid overflow.
Line your baking dish with parchment paper or foil with overhang for easy lifting and clean cuts.
Stir the mixture halfway through cooking to prevent hot spots or burning.
For cleaner slicing, chill the bars fully (at least 2–3 hours) before cutting—use a sharp knife dipped in hot water.
If your peanut butter is very thick, warm it slightly before mixing for smoother incorporation.
Avoid high heat; low is key to prevent scorching the chocolate.
Spray the slow cooker insert lightly with oil if not using a liner for easier release.

Ingredients Notes

The yellow cake mix forms the sturdy yet tender base that holds up beautifully in the slow cooker, absorbing moisture from the peanut butter and sweetened condensed milk for a chewy texture. Creamy peanut butter (not natural, as it can separate) delivers that classic rich, nutty flavor—smooth brands like Jif or Skippy work best for consistent results.

Unsalted butter adds richness and helps bind everything together when melted. Eggs provide structure and moisture to keep the bars from becoming too dense. Sweetened condensed milk is the secret to ultra-fudgy, caramel-like richness that ties the peanut butter and chocolate layers together perfectly.

Semi-sweet chocolate chips melt into a glossy topping that hardens just enough for clean bites while staying soft and indulgent.

Variations and Substitutions

Want to customize? Swap the yellow cake mix for chocolate or devil’s food cake mix for deeper cocoa flavor. Use crunchy peanut butter instead of creamy if you love extra texture from peanut pieces. For a dairy-free version, choose plant-based butter, egg replacer, and dairy-free chocolate chips plus sweetened condensed coconut milk.

Try milk chocolate or dark chocolate chips for a sweeter or more intense topping. Add ½ cup chopped peanuts or Reese’s pieces into the base for more crunch. For a salted caramel twist, drizzle caramel sauce over the top before chilling. Gluten-free? Use a certified gluten-free yellow cake mix and double-check other ingredients. You can even swirl in some Nutella or Biscoff spread with the peanut butter for a fun flavor mash-up.

Storage Options

Store the cooled and cut bars in an airtight container at room temperature for up to 5 days (they stay soft and fudgy). For longer storage, refrigerate them in a sealed container for up to 10–12 days—the cold sets them firmer. Freeze individually wrapped bars in a freezer-safe bag or container for up to 2–3 months; thaw at room temperature for 30–60 minutes before enjoying.