Oreo Ice Cream Cake

Preparation - Line a round 8x3-inch springform pan with plastic wrap. Use one sheet of plastic wrap to cover the base of the pan and another longer sheet of plastic wrap to line the sides. Clasp the ring and base together and put the pan in the freezer while you make the ice cream.

No-Churn Ice Cream - Place 6 Oreos in a resealable plastic bag, seal, and use a rolling pin to crush the Oreos into small pieces, no bigger than 1/4 to 1/2-inch. Set aside the Oreos and reserve the bag for later use.

No-Churn Ice Cream - In a large bowl, stir together the sweetened condensed milk, vanilla extract, and salt to combine. In another large bowl, whip the cold heavy cream to stiff peaks using an electric hand mixer on medium speed, 3 to 4 1/2 minutes. Alternatively, you can use a stand mixer fitted with the beater attachment.

No-Churn Ice Cream - Add 1/3 of the whipped cream to the bowl with the condensed milk mixture and fold in using a rubber spatula until almost fully combined. Fold in the remaining whipped cream in two additions until fully combined and there are no streaks.

No-Churn Ice Cream - Spoon half of the ice cream into a separate bowl and set aside. This will be the vanilla layer. Fold in the crushed Oreos into the remaining ice cream. This will be the cookies and cream layer. Place the cookies and cream base into the fridge while you work on the bottom layers of the cake.

Building the Cake - Remove the prepared pan from the freezer. Using a small offset spatula or the back of a spoon, spread a very thin layer of the vanilla ice cream, about 1/4 cup, over the bottom of the pan.

Building the Cake - Pour the milk into a small bowl. Working with one at a time, submerge each flat side of the 14 whole Oreos into the milk until soaked but not falling apart (about 6 seconds per side). Let the excess milk drip back into the bowl and place in a single layer on top of the thin layer of vanilla in the pan. Spoon any leftover milk over the Oreos and let fully absorb.

Building the Cake - Spoon the rest of the vanilla ice cream over the Oreos and smooth into an even layer. Transfer the pan back to the freezer and freeze until the surface is firm, 45 minutes to 75 minutes, depending on your freezer. It doesn't have to be solid all the way through, but firm enough that spreading fudge over the surface won't make it collapse.

Crunchies - While the vanilla layer freezes, make the crunchies. Preheat the oven to 350°F with a rack set in the middle. Line a small rimmed baking sheet with parchment paper.

Crunchies - Place the 10 Oreos in the resealable plastic bag, seal, and use a rolling pin to crush into fine, sandy crumbs. Alternatively, you can pulse the Oreos in a food processor. Transfer the crumbs to a medium bowl along with a pinch of kosher salt and the melted butter and toss until combined.

Crunchies - Spread the Oreo mixture onto the baking sheet in an even layer and bake until fragrant and matte, about 8 minutes. The Oreo crumbs will be soft when they come out of the oven and firm as they cool. Let cool.

Crunchies - If using the chocolate shell, transfer the crumbs to a bowl, breaking up any big clumps. Drizzle the chocolate shell over the crumbs and toss with a spoon until well coated. Set aside until you're ready to use.

Fudge - The fudge needs to be easily spreadable, but not hot. If using store-bought fudge from a new jar, it likely won't need to be heated. Just take care to give it a good stir. If using fudge that has been refrigerated, reheat the fudge in the microwave in 5-second intervals, stirring between each, until the fudge is spreadable but not hot.

Assembly - Once the surface of the vanilla layer is firm, working quickly, remove the pan from the freezer. Use a small offset spatula or the back of a spoon to spread the fudge in an even layer over the vanilla ice cream. Sprinkle the crunchies over the fudge. Return the pan to the freezer and chill until the layer of crunchies is firm, about 15 minutes.

Assembly - Remove the pan from the freezer and the cookies and cream ice cream from the refrigerator. Spoon the cookies and cream ice cream over the crunchies and use an offset spatula to spread it into an even layer. Cover the pan in plastic wrap, taking care not to create any dips in the ice cream. Return the pan to the freezer and freeze the cake until solid, at least 6 hours, but ideally overnight.

Whipped Cream - When the cake is frozen solid and you're ready to decorate, prepare the whipped cream. Add the cold heavy cream, powdered sugar, vanilla extract, and a pinch of kosher salt to a large bowl with a hand mixer or the bowl of a stand mixer fitted with the whisk attachment. Whip on medium speed until the cream is just about to reach stiff peaks, about 4 minutes. You should have about 3 cups. Reserve 1 cup for piping.

Unmolding - Take the cake out of the freezer. Leave the top piece of plastic wrap lying on top of the cake (this will act as a barrier from the heat of your hand when you flip the cake). Unlock the clasp to release the ring from the base and remove the ring.

Unmolding - Working quickly, with one hand under the base and one hand on top, flip the cake over, remove the base from the springform pan, peel the plastic wrap away, and flip it onto your cake board, plate, or platter. The vanilla and Oreo layer should be back on the bottom. Remove all the plastic wrap.

Frosting - If you have one, place the cake on a turntable. Scoop the whipped cream onto the top of the cake and use an offset spatula to work the cream across the top and down over the sides. Use a bench scraper, offset spatula, or another straight-edged tool to scrape a thin layer of the whipped cream and smooth out the sides.

Frosting - For a bit of finesse, hold a small offset spatula or small spoon with the tip just touching the center of the top of the cake. With your other hand, continuously rotate the cake stand. As the cake stand is rotating, slowly start to pull the spatula back towards the edge of the cake through the whipped cream to create a spiral design.

Frosting - Carefully transfer the cake back to the freezer to firm up the whipped cream, about 15 minutes.

Decorating - Transfer the reserved whipped cream to a piping bag fitted with a 1/2-inch star tip. Finely crush 1 Oreo in the resealable bag with a rolling pin for sprinkling over the top border, if desired. If using chocolate shell, transfer it to a plastic piping bag or resealable plastic bag with a small opening cut from the tip.

Decorating - Remove the cake from the freezer. Using the piping bag with chocolate shell (or alternatively small spoonfuls), create the chocolate drips around the perimeter of the cake by carefully piping the chocolate around the edge and letting it drip and set. Use the piping bag filled with whipped cream to pipe large rosettes over the top border of the cake. Sprinkle the piped border with crushed Oreos and add the remaining 8 to 10 whole Oreos to the top as desired. Return the cake to the freezer for one final freeze for at least 20 minutes, or until solid.