This Easy Retro Dessert Features a Jaw-Dropping Amount of Chocolate

If you've ever looked at a chocolate pie and thought to yourself, "I wish this had more chocolate," then Mississippi mud pie is for you. Each of its three mouthwatering layers—crunchy chocolate cookie crust, fudgy brownie center, and creamy pudding top—features an eye-bulging amount of chocolate. And while the different layers of this intense chocolate pie are said to be named for the Mississippi River's silty bottom, there's nothing muddy about its flavor or texture.

To create this mighty chocolate experience, our Birmingham, Alabama-based test kitchen colleague Elizabeth Mervosh baked pie after pie before landing on this chocolate-laden recipe below. Here's how to perfect each layer in this delightfully indulgent chocolate dessert.

The Perfect Crispy Chocolate Crust Requires Just Three Ingredients This effortless chocolate cookie crust relies on just three ingredients—cookie crumbs made from chocolate sandwich cookies (such as Oreos), melted butter, and salt—to deliver a crust that's pleasantly sweet and rich in flavor. Simply pulse chocolate cookies in a food processor, then combine the crumbs, butter, and a bit of salt in a bowl, and finally press the mixture evenly into a pie plate.

We like using store-bought or homemade Oreo cookies . In our tests, we found it best (and easiest) to keep the filling with the cookies—the filling enhances the crust's creamy texture, making it easier to press and mold into the pie plate. Or if you prefer, you can use the same weight of unfilled chocolate wafers, such as Nabisco brand, though the crust will be slightly less rich and sweet.

A Brownie Layer With a Rich Flavor but Light Texture We wanted a brownie layer that was rich and fudgy, but that was also light enough in texture that it was easy to break off bite-size pieces with a fork once baked—after all, you don't want to have to slice each individual bite of pie with a knife. The trick to getting this lighter texture with our brownies is whipping the eggs until they have tripled in volume and have the texture of runny marshmallows before folding them into the batter. This whipped egg mixture leavens the brownie layer and gives it an airy texture that pairs well with the other layers in the pie.

While we wanted our brownie batter to bake up light and fluffy, we still wanted it to have that signature brownie chew. Our tests revealed that the secret to the perfect chewy texture boils down to one thing: fat—specifically the ratio of saturated to unsaturated fat. By using both butter (a predominantly saturated fat) and vegetable oil (an unsaturated fat) in an approximately one–to-one ratio, we are able to produce a brownie layer with a satisfying chew that's still soft enough to run a fork through.

To intensify the brownie's chocolaty punch, in addition to using melted bittersweet chocolate in the brownie layer, we added cocoa powder to the mix: Ounce for ounce, cocoa powder has more cocoa solids—and thus more chocolate flavor—than any other type of chocolate, so a mere three tablespoons greatly enhances the brownie layer's flavor without creating the denser texture that using additional melted chocolate would result in.

The Creamiest Chocolate Pudding On top of the fudgy brownie is a light, creamy chocolate pudding. Instead of whisking the pudding mixture together on the stovetop, as most traditional pudding recipes do, here the pudding is pulsed and combined until smooth in a food processor. As the hot cream mixture is slowly poured into the chopped chocolate mixture in processor, the sharp blade guarantees every bit of chocolate blends into the mixture for the smoothest pudding possible.

The pie filling gets its rich flavor from—you guessed it—even more chocolate, in the form of bittersweet chocolate. We recommend skipping the chips and instead use a high quality bar chocolate with about 64 to 70% cacao. Chocolate chips often contain stabilizers like soy lecithin that prevent them from melting fully—that's great in chocolate chip cookies, but not so much in a pudding. So for a creamy, smooth chocolate pudding, you're better off starting with a bar and chopping it yourself. And finally, to safeguard your pudding's creamy texture and to make sure you don't end up with scrambled eggs, remember to temper the egg yolks so they don't curdle by slowly pouring the hot cream mixture into the food processor while running.

Whipped Cream Makes Almost Everything Better We love the juxtaposition of the dense chocolate pie with fluffy whipped cream topping. And for a decorative and appropriately Southern finish, we recommend sprinkling the pie with crunchy pecans. If you're not a fan of nuts, top the pie with simple chocolate shavings, crushed chocolate cookies, or absolutely nothing at all.