Corn Flakes or Rice Krispies can be substituted for the feuilletine in a pinch.
For the fudge sauce:
1 ounce 72 percent chocolate, chopped
2 tablespoons cocoa powder
1/8 teaspoon kosher salt
1/4 cup glucose
2 tablespoons sugar
1/4 cup heavy cream
For the chocolate cake:
1 stick butter, room temperature
1 1/2 cups granulated sugar
1/2 cup buttermilk
1/4 cup grape-seed oil
3 tablespoons fudge sauce
1 teaspoon vanilla extract
1 1/4 cups cake flour
1/2 cup cocoa powder
1 1/2 teaspoons baking powder
1 1/2 teaspoons kosher salt
For the chocolate malt cake soak:
1/4 cup milk
2 tablespoons Ovaltine powder
For the crack-coconut filling:
2/3 cup granulated sugar
3 tablespoons light brown sugar
1 tablespoon milk powder
1 tablespoon corn powder
1/2 teaspoon kosher salt
4 tablespoons butter, melted
3 tablespoons heavy cream
1/4 teaspoon vanilla extract
2 egg yolks
1 cup sweetened coconut
For the pecan crunch:
3/4 cup pecans, chopped
Splash grape-seed oil
1/2 teaspoon salt
1 tablespoon light brown sugar
3/4 cup feuilletine 
For the chocolate malt frosting:
1 stick butter, room temperature
1 cup powdered sugar
1/2 teaspoon kosher salt
1/4 cup cocoa powder
2 tablespoons whole milk
1/4 cup sweetened coconut, toasted, for garnish
1 (6-inch) cake ring 
2 strips acetate , each 3 inches wide and 20 inches long
- Make the fudge sauce: Combine the chocolate, cocoa powder, and salt in a medium bowl.
- Combine the glucose, sugar, and heavy cream in a heavy-bottomed saucepan, and stir intermittently while bringing it to a boil over high heat. The moment it boils, pour it into the bowl holding the chocolate. Let sit for 1 full minute.
- Slowly, slowly begin to whisk the mixture. Then continue, increasingly the vigor of your whisking every 30 seconds, until the mixture is glossy and silky smooth. This will take 2 to 4 minutes, depending on your speed and strength. You can use this sauce at this point, or store it in an airtight container in the fridge for up to 2 weeks; do not freeze.
- Make the chocolate cake: Heat the oven to 350°F.
- Combine the butter and sugar in the bowl of a stand mixer fitted with the paddle attachment, and cream together on medium high for 2 to 3 minutes. Scrape down the sides of the bowl, add the eggs, and mix on medium high for 2 to 3 minutes. Scrape down the sides of the bowl once more.
- On low speed, stream in the buttermilk, oil, fudge sauce, and vanilla. Increase the mixer speed to medium high, and paddle for 4 to 6 minutes, until the mixture is practically twice the size of your original fluffy butter-and-sugar mixture and completely homogeneous. Don't rush the process. You're basically forcing too much liquid into an already fatty mixture that doesn't want to make room for that liquid. There should be no streaks of fat or liquid. Stop the mixer, and scrape down the sides of the bowl.
- On very low speed, add the cake flour, baking powder, salt, and cocoa powder. Mix for 45 to 60 seconds, just until your batter comes together. Scrape down the sides of the bowl.
- Spray a quarter sheet pan with nonstick cooking spray, and line it with parchment, or just line the pan with a Silpat. Using a spatula, spread the cake batter in an even layer in the pan.
- Bake the cake for 30 to 35 minutes. The cake will rise and puff, doubling in size, but will remain slightly buttery and dense. At 30 minutes, gently poke the edge of the cake with your finger: the cake should bounce back slightly, and the center should no longer be jiggly. Leave the cake in the oven for an extra 3 to 5 minutes if it doesn't pass these tests.
- Take the cake out of the oven, and cool on a wire rack or, in a pinch, in the fridge or freezer (don't worry, it's not cheating). The cooled cake can be stored in the fridge, wrapped in plastic wrap, for up to 5 days.
- Make the malt cake soak: Whisk together the milk and Ovaltine in a small bowl.
- Make the crack-coconut filling: Heat the oven to 325°F.
- Combine the granulated sugar, brown sugar, milk powder, corn powder, and salt in the bowl of a stand mixer fitted with the paddle attachment, and mix on low speed until evenly blended.
- Add the melted butter, and paddle for 1 minute until all the dry ingredients are moist.
- Add the heavy cream and vanilla, and continue mixing on low for 1 minute until any white streaks from the cream have completely disappeared into the mixture. Scrape down the sides of the bowl with a spatula.
- Add the egg yolks, paddling them into the mixture just to combine. Be careful not to aerate the mixture, but be certain the mixture is glossy and homogeneous. Mix on low speed until it is.
- Line the bottom and sides of a small baking pan with plastic wrap. Pour the crack pie filling into the pan, put the pan into the oven, and bake for 8 to 10 minutes. Gently shake the pan. The crack pie filling should be firmer and more set toward the outer boundaries of the baking pan but slightly jiggly and loose in the center. If the crack pie filling is jiggly all over, give it 2 to 3 minutes.
- Once cooled, mix the crack pie filling with the sweetened coconut. This filling can be used immediately or stored in an airtight container in the refrigerator for a week.
- Make the pecan crunch: Heat the oven to 325°F.
- Put the pecans on a sheet pan, and toast them in the oven for 15 minutes.
- Puree the warm pecans in a food processor with a splash of grape-seed oil, salt, and light brown sugar.
- In a small bowl, combine the pecan puree with the feuilletine. The crunch can be stored in an airtight container at room temperature for 5 days or in the fridge for up to 2 weeks.
- Make the chocolate malt frosting: Combine the butter, sugar, salt, and cocoa powder in the bowl of a stand mixer fitted with the paddle attachment, and cream them together on medium high for 5 to 7 minutes, until the mixture is smooth and fluffy. Scrape down the sides of the bowl.
- With the mixer at its lowest speed, stream in the milk. Crank the mixer up to medium high, and beat for 2 to 3 minutes, until the mixture is silky smooth and a glossy. Scrape down the sides of the bowl. Use the frosting immediately, or store it in an airtight container in the fridge for up to 1 week.
- Assemble the German chocolate Jimbo layer cake: Put a piece of parchment or a Silpat on the counter. Invert the cake onto it, and peel off the parchment or Silpat from the bottom of the cake. Use the cake ring to stamp out 2 circles from the cake. These are your top 2 cake layers. The remaining cake scraps will come together to make the bottom layer of the cake.
- Clean the cake ring, and place it in the center of a sheet pan lined with clean parchment or a Silpat. Use 1 strip of acetate to line the inside of the cake ring.
- Put the cake scraps together inside the ring, and use the back of your hand to tamp the scraps together into a flat even layer
- Dunk a pastry brush in the malt cake soak and give the layer of cake a good, healthy bath of the soak.
- Use the back of a spoon to spread 1/2 recipe of the crack-coconut filling in an even layer over the cake.
- Sprinkle half of the pecan crunch evenly over the crack-coconut filling. Use the back of your hand to anchor it in place.
- Use the back of a spoon to spread 1/3 of the chocolate malt frosting over the pecan crunch layer.
- With your index finger, gently tuck the second strip of acetate between the cake ring and the top 1/4 inch of the first strip of acetate, so you have a clear ring of acetate 5 to 6 inches tall — high enough to support the height of the finished cake. Set a cake round on top of the frosting, and repeat the process for layer 1 (if 1 of your 2 cake rounds is less attractive than the other, use it here in the middle, and save the prettier one for the top).
- Nestle the remaining cake round into the frosting. Cover the top of the cake with the remaining frosting. Give it volume and swirls, or do as we do and opt for a perfectly flat top. Garnish the frosting with toasted, sweetened coconut.
- Transfer the sheet pan to the freezer, and freeze for a minimum of 12 hours to set the cake and fillings. The cake will keep in the freezer for up to 2 weeks.
- At least 3 hours before you are ready to serve the cake, pull the sheet pan out of the freezer, and using your fingers and thumbs, pop the cake out of the cake ring. Gently peel off the acetate, and transfer the cake to a platter or cake stand. Let it defrost in the fridge for a minimum of 3 hours (wrapped well in plastic, the cake can be refrigerated for up to 5 days).
- Slice the cake into wedges, and serve.
- Cake, Desserts
- 1 6-inch layer cake, 5 to 6 inches tall, or 6 to 8 servings