These Mud Pie Bars are the perfect chocolate dessert for any chocolate lover. They have a layer of chocolate crumbs, followed by a layer of chocolate cake, then a layer of chocolate mousse. These chocolate mousse bars are then finished off with a layer of whipped cream and chocolate curls.
Table of contents
Mud Pie Bars from Sarah Kieffer's Book, 100 Cookies
Hi hi! Happy Tuesday - hope your week is going ok so far. I made these mud pie bars from Sarah Kieffer's latest book, '100 cookies' a few weeks ago, and am finallysharing the recipe with you!
Sarah's first book, 'The Vanilla Bean Baking Book', is probably one of the most used in my collection. Her recipes are amazing, work every time, and are so well written, so I will often turn to it for reference. It is so amazing that I just knew this new book would be incredible. And turns out, it's even more incredible than I could have even imagined.
The book is called '100 cookies' and is just that - 100 cookie recipes. There's her famous pan banging cookies, a section for brownies and blondies (my go-to brownie is her recipe!), then little treaty things, and a whole lot of bars and sandwich cookies. You're going to need to pick yourself up a copy ASAP.
The ultimate chocolate lover's dessert.
I had a really hard time deciding what to make from Sarah's book to share here, until I flipped to these mud pie bars. They are made up of four layers, so are a little more labour intensive than your standard bar. However, every second of work is 100% worth it, as the final outcome is rich and chocolatey - to me, this is the perfect chocolate dessert.
Four layers of Mud Pie Bars
Part of what makes these so, so impressive are the four layers, which are:
- Chocolate Crumbs: The first layer is a thin layer of chocolate crumbs. Sarah calls for chocolate wafer cookies. However I didn't have any, so I gutted some oreos and crushed those up instead, and they worked great.
- Chocolate Cake: The next layer is a chocolate cake layer poured over the chocolate crumbs. This cake is rich and dense, and provides the perfect base for what is coming next.
- Chocolate Mousse: A rich, silky, chocolate mousse is made and allowed to set, and then spread over the base and left to chill for a wee bit to firm up.
- Whipped Cream: Finally, the whole thing is finished off with a thin layer of whipped cream and a coating of chocolate curls. The cream cuts perfectly through the rich chocolate.
How to break up the work load of a complex baking project
These Mud Pie Bars have a few elements, so you can easily break up the work! Here's how I did it:
- Day one:
- Make the chocolate crumb layer and leave to cool.
- Bake the chocolate cake layer and leave to cool (it needs four hours in the fridge at least).
- Make the chocolate mousse and leave to set overnight.
- Day two:
- Add the chocolate mousse layer to the bars and leave to chill
- Add the whipped cream layer and serve!
FAQ for Mud Pie Bars
If you don't have chocolate wafers, Oreos work perfectly. I removed all the filling then ground up the cookies.
If you would like to make these gluten free it would be very easy, as the cake has very little flour in it. Just swap the all-purpose flour for a 1:1 gluten free swap, and use a gluten free oreo in the base.
These keep great in the fridge! Sarah said they are best after two days, but we had some on day five and they were still great. If you are worried you can leave off the whipped cream topping on half and add fresh cream at a later date.
Like this? See similar recipes:
❤️ Made this recipe and love it? ❤️
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Answers to your baking questions
Over the years, many of you have asked me questions about:
- baking in grams
- adjusting oven temperatures
- what kind of salt to use
- and many more!
I've curated and answered them all for your easy reference in this frequently asked questions post!
Mud Pie Bars
- Prep Time: 1 hour 30 minutes
- Cook Time: 40 minutes
- Total Time: 2 hours 10 minutes plus an overnight chill
- Yield: Makes 12 large or 24 small bars 1x
- Category: Dessert
- Cuisine: American
Description
These Mud Pie Bars are the perfect dessert for any chocolate lover. They have a layer of chocolate crumbs, followed by a layer of chocolate cake, then a layer of chocolate mousse. They are then finished off with a layer of whipped cream and chocolate curls.
Ingredients
Crust
- 200g chocolate wafer cookies or oreos with the filling taken out
- 70g unsalted butter, melted and cooled
Cake
- 225g semisweet or bittersweet chocolate
- 170g unsalted butter
- 2 Tbsp Dutch process cocoa powder
- 250g granulated sugar
- 5 large eggs, at room temperature
- 1 tsp vanilla extract
- ¼ tsp salt
- 36g all-purpose flour
Chocolate Mousse
- 600g heavy cream
- 5 large egg yolks, at room temperature
- 50g granulated sugar
- ¼ tsp salt
- 1 tsp vanilla extract or paste
- 225g semisweet or bittersweet chocolate, finely chopped
Whipped Cream
- 360g heavy cream
- 2 Tbsp granulated sugar
- 1 tsp vanilla bean paste or extract
- pinch of salt
Instructions
CHOCOLATE CRUST
- Adjust an oven rack to the middle of the oven. Preheat the oven to 350°f / 180°c.
- Grease a 9" x 13" (23 x 33cm) pan and line it with a parchment sling.
- Place cookies in the bowl of a food processor and process until broken down into fine crumbs. Move the crumbs to a medium bowl, and pour the melted butter over the top. Use a spatula to stir together until combined.
- Press the mixture onto the bottom of the prepared pan and bake for 10 minutes. Remove the pan from the oven and let cool.
CHOCOLATE CAKE
- Keep the oven temperature at 350°f / 180°c.
- In a small saucepan, melt the chocolate and butter together over low heat, stirring frequently, until smooth. Remove from the heat and stir in the cocoa powder.
- In a large bowl, whisk together the sugar, eggs, vanilla, and salt until smooth. Add the flour and mix again until combined. Add the warm chocolate and whisk into the batter until combined. Let the mixture sit for 15 minutes.
- Pour the cake batter over the cooled, baked crust and use an offset spatula to smooth the top.
- Bake the cake until the edges are set and the center jiggles slightly, 15 to 18 minutes. Remove from the oven and let cool completely on a wire rack. Cover the pan with plastic wrap and refrigerate for 4 hours, or overnight.
CHOCOLATE MOUSSE
- Heat 240g of the heavy cream in a small, heavy saucepan until hot.
- In a medium saucepan off the heat, whisk the egg yolks. Whisking constantly, slowly add the sugar to the egg yolks, then the salt, and then slowly pour in the warmed heavy cream. Cook over medium heat, stirring constantly, until the mixture registers 160°f / 70°c. Pour the mixture through a fine-mesh sieve into a large bowl and stir in the vanilla.
- In a small saucepan over low heat, melt the chocolate, stirring frequently until smooth. Whisk the chocolate into the custard until smooth, then let cool.
- In the bowl of a stand mixer fitted with the whisk attachment (or just using a mixing bowl and whisk), beat the remaining 360g heavy cream until stiff peaks form. Whisk one-third of the whipped cream into the chocolate custard to lighten it, then gently fold in the remaining whipped cream.
- Transfer the mousse to a large bowl and cover the bowl with plastic wrap. Refrigerate for 4 hours, or overnight.
WHIPPED CREAM
- Ten minutes before whipping the cream, place the bowl and whisk from a stand mixer (or a hand whisk) in the freezer and let chill. In the chilled bowl, whisk together the heavy cream, sugar, vanilla, and salt for 30 to 45 seconds. Increase the speed to medium and beat for 30 to 45 seconds. Increase the speed to high and beat until the cream is smooth, thick, and nearly doubled in volume, 30 to 60 seconds. The whipped cream can be made 2 hours ahead and stored in the fridge.
ASSEMBLY
- Transfer the chilled chocolate mousse onto the top of the baked, cooled cake. Use an offset spatula to even the top. return the bars to the fridge and let chill for 1 hour.
- When ready to serve, cover the bars with the whipped cream. Coat the top with grated chocolate, if desired. Use the parchment sling to remove the cake from the pan, and cut into slices. Bars can be stored in the fridge in an airtight container for up to 5 days.
Notes
Reprinted with permission from '100 Cookies' by Sarah Kieffer. Sarah uses table salt in her recipes which is 'saltier' than kosher. If you are using Kosher salt, increase your quantities.
Keywords: sarah kieffer, 100 cookies, mud pie, mud pie bars, chocolate
Comments
This was a huge hit! It takes a bit of time to make, but the plan ahead ideas were super helpful. These taste SO GOOD. It makes a lot though, so make sure you have friends to share with.
★★★★★
Yayyyyy I am so glad you like it! I distributed to so many friends! haha. xx
Is it ok to substitute natural cocoa for the Dutch processed?
I haven't tried it but it should be fine 🙂
This looks great =) Do you think I can freeze the whole thing and then defrost it in the fridge before serving? Maybe freeze without the whipped cream and then add the whipped cream after it’s defrosted?
Hi! I'm not sure sorry as I haven't tried it. I would definitely not freeze with the cream on. I haven't frozen mousse before but it should be ok? I would just assemble ahead and add cream before serving 🙂
All of my friends that I did socially distant baked good drops with LOVED this recipe and begged me to make this again! Absolutely delicious!
★★★★★
Ah yayyyy I LOVED them so much when I made them! I took some to my Sister in Law and her bf and apparantely he's still asking about them!
I made this recipe for my mom's birthday! My family are all chocolate lovers and they all LOVED it! It was also fun to make all the different layers:) Delicious and fancy! I don't have a kitchen scale, so I just used google to make the conversions:)
★★★★★
Ahhh I am so glad you love! xx
I love that you always seem to make sure your eggs are heated to the safety point. Not all food bloggers do that. That extra effort is appreciated. I am looking forward to making these....although in pandemic lockdown, there is no one to share them with🙁.o
Ahhh so happy you enjoy the recipes! Thank you so much for the sweet comment!
SOOOO GOOD! I don’t think I let each layer set up properly so I wasn’t able to slice, so I ended up putting it in the freezer and it turned into the yummiest frozen dessert. The cake layer was so good I’m considering making it on its own. Will def make again!
Probably (definitely) the best thing I made during covid- SUCH a treat and fun make to make. Worth it!
★★★★★
These bars are a labor of love, but so worth it! The flavors are amazing and are probably worthy of a fancier title. I halved the recipe into an 8x8 and it worked well!
★★★★★
Your final note states Sarah uses table salt, and if using kosher salt we should increase the amount. So, how many grams of kosher salt should someone use instead?
Thank you.
Table salt is about half as salty as Diamond Crystal kosher salt, so if you are using that, you would double the quantity called for in the recipe 🙂
Isn’t it the reverse? Table salt is saltier…..
Yes you're right thank you for catching that! Will edit the post
Oh my gosh, Erin! These look delicious, I can't wait to try them!
These were delicious! I made them over the course of two days and they came out just like your pictures. Next time I may try subbing the chocolate mouse layer for coffee ice cream. The recipe makes a ton. Thanks for the great recipe!
★★★★★
These are FANTASTIC!! I just barely discovered Cloudy Kitchen, so I've only made a few different recipes so far. But all of them are so delicious. Thank you!
★★★★★