Chocolate Malt Cake

For the milk crumbs:
Preheat oven to 275°F. Line a half sheet pan with parchment paper.

Combine milk powder, flour, sugar, cornstarch, and salt in medium bowl and whisk together. Stir in melted butter with a fork until clusters form.

Pour mixture and spread evenly on sheet pan. Bake for about 10 minutes until crumbs are dry and crumbly but still pale.

Cool milk crumbs completely on sheet. Can be made 1 week ahead. Store in airtight container at room temperature.

For the chocolate malt crumbs:
Mix milk crumbs and Ovaltine in a small bowl. Melt white chocolate in a microwave-safe bowl, 15 seconds at a time, until just melted. Drizzle chocolate over crumb mixture. Stir to coat.

For the malt fudge sauce:
Place Ovaltine, bittersweet chocolate, light molasses and salt in a medium bowl; set aside. Bring cream, corn syrup, and sugar to a boil in a saucepan, stirring until sugar is dissolved. Pour cream mixture over chocolate mixture in bowl. Let stand 1 minute to melt the chocolate, then stir until smooth. Whisk until sauce is glossy, about 1 minute. Can be made 1 week ahead of time, just cool completely. Cover and refrigerate. Rewarm in microwave 30 seconds at a time just until pourable before using.

For the cake:
Preheat oven to 350°F. Coat three 9-inch cake pans with nonstick cooking spray. Line bottom of each pan with parchment round and coat parchment with nonstick cooking spray.

Melt bittersweet chocolate in small microwave-safe bowl, 15 seconds at a time, until just melted. Set aside.

Sift flour, cocoa powder, baking powder, and salt into medium bowl and set aside. Combine butter, sugar, and corn syrup in bowl of a stand mixer fitted with paddle attachment. Beat on medium-high speed until fluffy and pale, about 2 minutes. Scrape down sides of bowl. Add eggs and beat on low speed to incorporate, then increase speed to medium-high and beat until mixture is light and fluffy, about 2 minutes.

Scrape down sides of bowl. Add melted chocolate. Beat until blended, about 1 minute. Add buttermilk, oil, and vanilla and beat on medium-high speed until pale brown, about 2 minutes. Add dry ingredients and beat on low-speed just until blended, about 45 seconds. Divide batter among three 9-inch cake pans and smooth tops.

Bake cakes 15–20 minutes or until an inserted toothpick comes out clean. Cool completely in pans on wire cooling racks.

Stir milk and Ovaltine together in a small bowl. Invert 1 cake, top side down, from pan onto a flat surface (like the bottom of a springform pan) and peel off parchment. Brush cake with 2 1/2 tablespoons of the Ovaltine-milk mixture. Let Ovaltine-milk mixture soak into the cake for 1 minute. Drizzle about a 1/2 cup malt-fudge sauce over the cake, so it coats the entire top of the cake. Spread out evenly. Sprinkle 1/2 cup chocolate malt crumbs over sauce. Drizzle another 1/3 cup malt-fudge sauce over crumbs. Scatter 1 cup mini marshmallows on top of the crumbs. Using a kitchen torch, toast marshmallows. Repeat the entire process with second cake layer, Ovaltine-milk mixture, malt-fudge sauce, chocolate-malt crumbs, malt-fudge sauce, and marshmallows.

Remove third cake from pan and peel off parchment. Place cake, top side down, on top of the marshmallows of the second cake layer. Brush with remaining Ovaltine-milk mixture. Cover cake and remaining fudge sauce with plastic wrap and refrigerate overnight. Pop the leftover chocolate milk crumbs in an airtight container and store overnight at room temperature.

Once chilled overnight, place cake (still on springform pan bottom) on a cake serving plate. Rewarm sauce in the microwave, 30 seconds at a time, until just pourable. Pour over top of cake, allowing the sauce to drip over edges. Add a handful of marshmallows in center of cake. Using kitchen torch, toast marshmallows. Sprinkle the remaining malt crumbs over cake. Let cake stand at room temperature 3 hours before serving.

Cut cake into wedges and serve.

Recipe adapted from Christina Tosi.