Chocolate Mud Bars Recipe with Oreo Crust and Brownie Layer

Chocolate Mud Bars

Chocolate Mud Bars are the layered chocolate dessert I bring when I want a tray to vanish before the plates are cleared.

The build starts with an Oreo cookie crust, then a fudgy brownie layer, then a silky chocolate mousse layer, and finally hot fudge with whipped cream on top. Each bite gives you crunch, dense fudge, and airy mousse at the same time.

It is the kind of dessert that looks like an all day project, but the whole thing is a simple bake and chill job. If you love chocolate in more than one texture, this recipe earns its spot in your rotation.

Ingredients & Substitutions

Because these bars have four parts, it helps to know where you have wiggle room and where you do not. Here is how I think about each layer before I start pulling ingredients.

The crust

Thirty Oreo cookies give you the deep chocolate base, and a food processor is the fastest way to get the fine, even crumb you want. Whole cookies, cream and all, go straight into the bowl.

Scoop out about 1/4 cup of crumbs before you mix anything and save them for the topping later. The remaining crumbs get stirred with melted butter until the mixture holds together when you press it into the pan.

If you are out of Oreos or want a different flavor, a chocolate wafer crust works as a substitute. It comes out a little less sweet, and I like it when I want the brownie layer to carry the sweetness on its own.

The brownie layer

This is my go to brownie recipe for a 9×13 inch dish, and it is the same one I use in my French Silk Brownies. That means you are not building a separate batter for this dessert. You are making a brownie you already trust and pouring it over the cookie crust.

The chocolate mousse layer

A 3.9 ounce package of chocolate instant pudding mix does the heavy lifting here. Use whole milk for the creamiest result. Two percent or one percent milk will still work, but the mousse will be noticeably less rich, so if you have whole milk on hand, use it.

The whipped cream

Homemade whipped cream is the creamiest option, but store bought whipped topping is a perfectly fine shortcut and it holds its shape well. You need 16 ounces total. Half goes into the mousse layer and the rest is saved for the top.

The hot fudge

Use a homemade chocolate syrup or a jar of hot fudge sauce. Either one drizzles nicely over the chilled mousse, and either one disappears into the layers in the best way.

A note on the pan

This recipe is built for a 9×13 inch baking dish. A smaller pan gives you thicker layers that set differently, and a larger pan spreads everything too thin. Stick with the size the recipe calls for and the layers will stack the way they should.

Can I Make These Bars Ahead Of Time?

Yes, and honestly the make ahead route is the one I recommend, because the bars have to chill anyway.

The crust and brownie portion can be baked, cooled, and stored in a sealed container on the counter for a day or two. The mousse layer can be mixed and kept in the refrigerator overnight. Then you just spread the chilled mousse over the brownies and finish with the fudge and whipped topping.

The assembled bars need to be refrigerated before serving, so planning ahead is built into this dessert. If you are feeding a crowd on Saturday, bake the base on Friday and finish it Saturday morning.

Do not rush the cooling step. A fully cooled brownie layer is what keeps the mousse sitting neatly on top instead of sliding around.

How To Store Chocolate Mud Bars

Store Chocolate Mud Bars covered in the refrigerator, where they will keep for up to 3 to 4 days. Because the mousse and the whipped topping are dairy based, the refrigerator is not optional here.

For the cleanest slices, chill the bars thoroughly and use a sharp knife wiped clean between cuts. The crust can crumble if you saw at it, so press straight down and lift the slice out with a small spatula.

When our Test Kitchen tasters tried these bars, they came back with a lot of love for the layered approach. Everyone enjoyed the combination of Oreos, brownies, chocolate mousse, and whipped cream, with hot fudge drizzled over the top.

One taster said the mousse layer was a favorite and would happily eat it on its own, and thought the dessert would be a hit at a potluck or a gathering.

Another taster picked up the familiar Oreo chocolate flavor right away and liked the texture that came from the smooth mousse and whipped topping.

That taster also found the sweetness subtle rather than extreme, even with the brownie underneath, and mentioned that the hot fudge was not necessary in their opinion.

I still drizzle it. Warm fudge against cold mousse is a contrast I am not willing to give up, but it is good to know the bars hold up beautifully without it if you prefer a lighter finish.

This is also why the bars travel so well to a church supper or a picnic table. Keep the pan cold until you leave, set it down in the shade, and slice as people come through the line.

The layers hold their shape long enough to serve a crowd, and the reserved cookie crumbs on top keep the surface from looking messy.

Ingredients

This recipe makes 12 large bars in a 9×13 inch pan. Here is the full list, grouped by layer so you can shop and measure without guessing.

Crust

• 30 Oreo cookies
• 1/2 cup (1 stick or 113 g) unsalted butter, melted

Brownie layer

• 1 1/2 cups (187.5 g) all purpose flour
• 1/3 cup (42 g) regular unsweetened cocoa powder
• 1/2 teaspoon baking powder
• 1/4 teaspoon kosher salt
• 4 large eggs, room temperature
• 2 cups (400 g) granulated sugar
• 3/4 cup (1 1/2 sticks or 170 g) unsalted butter, room temperature
• 2 teaspoons vanilla

Chocolate mousse layer

• 2 cups (490 g) whole milk
• 1 package (3.9 ounces) dry instant chocolate pudding mix
• 1/2 cup (62.5 g) confectioners’ sugar
• 16 ounces whipped topping, divided
• 1 jar (11.75 ounces) hot fudge topping

Instructions

1. Preheat the oven to 350 degrees Fahrenheit. Spray a 9×13 inch baking dish with nonstick spray.
2. Make the crust. Using a food processor, process the Oreo cookies until they are a fine crumb. Set aside 1/4 cup of crumbs for the topping. In a large bowl, combine the remaining cookie crumbs with the melted butter until fully incorporated. Press the cookie mixture into the baking dish and set aside.
3. Mix the dry brownie ingredients. To a large bowl add the flour, cocoa powder, baking powder, and salt. Whisk the ingredients together until they are fully incorporated.
4. Mix the wet brownie ingredients. In the bowl of a stand mixer, or in a large bowl using a hand held mixer, beat the eggs, sugar, butter, and vanilla until light and fluffy.
5. Combine the batter. With the mixer off, add the flour mixture. Turn the mixer on low and mix until the ingredients are well combined.
6. Bake the brownie layer. Carefully pour the brownie batter into the prepared baking dish, over the Oreo cookie crust. Bake for 25 to 30 minutes, or until just barely set. Keep a close eye on it, because you are looking for a fudgy layer. A toothpick inserted in the center will have a small amount of wet batter. Set aside to cool to room temperature.
7. Make the mousse. In another large bowl, beat the milk, pudding mix, and confectioners’ sugar until soft set, about 2 minutes. Fold in 8 ounces of whipped topping and continue folding until fully combined.
8. Spread the mousse. Spread it over the cooled brownie layer. Do not put the mousse on hot brownies, so make sure the layer is mostly cooled first.
9. Chill. Transfer the bars to the refrigerator to chill for at least 1 to 1 1/2 hours.
10. Finish the bars. Once chilled, drizzle the hot fudge over the mousse. Top with the remaining whipped cream and the reserved cookie crumbs.
11. Serve. Enjoy immediately or store in the refrigerator until ready to serve.

The brownie layer is the one place where patience pays off. Pull it when the center still looks slightly underdone and you will get that soft, fudgy middle that makes these bars worth the wait.

Recipe details

Prep time is 15 minutes, cook time is 25 minutes, and chilling time is 1 hour, for a total time of 1 hour 40 minutes. The recipe makes 12 large bars, and one bar per serving comes in at 681 calories.

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Chocolate Mud Bars

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Chocolate Mud Bars Chocolate Mud Bars are the layered chocolate dessert I bring when I want a tray to vanish before the plates are cleared. The build starts with an Oreo cookie crust, then a fudgy brownie layer, then a silky chocolate mousse layer, and finally hot fudge with whipped cream on top.

• Total Time: 100 min
• Yield: 12 large bars 1x

Ingredients

Scale 1x2x3x

Crust
30 Oreo cookies
½ cup unsalted butter, melted

Brownie Layer
1 ½ cups all-purpose flour
⅓ cup regular unsweetened cocoa powder
½ teaspoon baking powder
¼ teaspoon kosher salt
4 large eggs, room temperature
2 cups granulated sugar
¾ cup unsalted butter, room temperature
2 teaspoons vanilla

Chocolate Mousse Layer
2 cups whole milk
1 package (3.9 ounces) dry instant chocolate pudding mix
½ cup confectioners’ sugar
16 ounces whipped topping, divided
1 jar (11.75 ounces) hot fudge topping

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Instructions

1-Preheat the oven to 350°F: Preheat the oven to 350°F. Spray a 9×13-inch baking dish with non-stick spray.
2-Using a food processor, process Oreos cookies: Using a food processor, process Oreos cookies until they are a fine crumb. Set aside ¼ cup crumbs for the topping. In a large bowl, combine the remaining cookie crumbs with melted butter until fully incorporated. Press cookie mixture into the baking dish. Set aside.
3-To a large bowl add flour, cocoa,: To a large bowl add flour, cocoa, baking powder, and salt. Whisk together ingredients until they are fully incorporated. In the bowl of a stand mixer or in a large bowl using a hand-held mixer beat the eggs, sugar, butter, and vanilla until light and fluffy. With the mixer off, add the flour mixture. Turn the mixer on low and mix until the ingredients are well combined. Carefully pour brownie batter into the prepared baking dish, over the Oreo cookie crust. Bake for 25-30 minutes, or until just barely set. (Keep a close eye on it, looking for a fudgy layer). A toothpick inserted in the center will have a small amount of wet batter. Set aside to cool to room temperature.
4-In another large bowl, beat the milk,: In another large bowl, beat the milk, pudding mix, and confectioners’ sugar until soft-set (about 2 minutes). Fold in 8 ounces of whipped topping and continue folding until fully combined. Spread over the cooled brownie layer. (Don’t put the mousse on hot brownies; make sure the layer is mostly cooled.) Transfer the bars to the refrigerator to chill for at least 1-1 ½ hours. Once chilled, drizzle hot fudge over the mousse. Top with the remaining whipped cream and reserved cookie crumbs. Enjoy immediately or store in the refrigerator until ready to serve.

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• Prep Time: 15 min
• Cook Time: 25 min
• Method: bake

Nutrition

• Serving Size: 1bar
• Calories: 681kcal