A Very Particular Cake, Triple-Layer Vanilla Cacao Nib with Passion Fruit Curd and Coffee Frosting

This morning I woke up, brewed some coffee, made a fruit salad, and decided that today was the day to superlatively discuss cake.  A painstaking cake.  Supremely vanilla with its top frosted in coffee icing and its insides stuck together with passion fruit curd, studded with cacao nibs.

I am here to say confection doesn’t get much better than this.

The downside to discovering the greatest cake in the world is that it is even more of a pain in the ass to write about.  The recipe is really a collection of five smaller recipes, which means if you are interested in eating the greatest cake in the world you’ve got your work cut out for you.

You could also try and befriend someone you deem mad enough to take on such a project.  But even this has its downsides. Those who complete such tasks are usually quite particular people.  Adjectives such as stubborn and quixotic come to mind. 

Moving on.

The recipe comes from Milk Bar, of the Momofuku fame.  It was originally very modern in design.  Its frosting insides clearly visible from the outside. Three-tiered layers standing trim and tall and capable of serving six to eight people. 

However, this required acetate strips, a 6-inch cake ring, and the abolishment of a half dozen friends.  So my version is a little stockier.  A little less refined. And with the addition of cacao nibs instead of mini chocolate chips.  Because I’m particular when it comes to chocolate.

All and all it’s an outstanding cake, capable of comfortably feeding a baker's dozen.  People whom you must like very much.

Triple-Layer Vanilla Cacao Nib Cake with Passion Fruit Curd and Coffee Frosting

Adapted from Momofuku Milk Bar by Christina Tosi

Ingredients:

for the passion fruit syrup

5 passion fruit

50 g (¼ cup) sugar

juice of ½ a lime

pinch of salt

splash of vanilla extract

for the passion fruit curd (this will make extra)

200 g (1 cup) passion fruit puree (see note below)

130 g (2/3 cup) sugar

4 eggs

1 tsp powdered gelatin

340 g (3 sticks) butter, cold and cut into 1-inch pieces

2 g (½ tsp) kosher salt

for the chocolate cookie crumbs

50 g (1/3 cup) flour

2 g (½ tsp) cornstarch

50 g (¼ cup) sugar

35 g (1/3 cup) unsweetened cocoa powder

2 g (½ tsp) kosher salt

45 g (3 tbsp) butter, melted

for the vanilla cacao nib cake

230 g (2 sticks) butter, room temperature

500 g (2½ cups) sugar

120 g (½ cup) light brown sugar, packed

6 eggs

220 g (1 cup) buttermilk

150 g (1 cup) canola oil

25 g (2 tbsp) vanilla extract

370 g (3 cups) cake flour (see note)

8 g (2 tsp) baking powder

8 g (2 tsp) kosher salt

1½ cups chocolate covered cacao nibs, divided

for the coffee frosting

230 g (2 sticks) butter, room temperature

80 g (½ cup) confectioners sugar (sift if it’s clumpy)

110 g (½ cup) whole milk

3 g (½ tbsp) instant espresso powder (I’ve used up to 1 scant tbsp)

1 g (¼ tsp) kosher salt

Directions:

for the passion fruit syrup

In a medium saucepan, combine the pulp from 5 passion fruit, sugar, juice, and salt.  Heat until the sugar dissolves and the mixture comes together, stirring occasionally (2 to 4 minutes; you should end up with a little more than ½ cup); stir in vanilla extract.  Refrigerate until ready to use. It will thicken slightly as it cools and should be the texture of runny marmalade. (This can be made well in advance; it can also be frozen: defrost before using.) 

for the passion fruit curd

In a food processor, add 1 cup passion fruit puree and the sugar and blend until the sugar granules have dissolved.  Add the eggs and blend until the mixture turns orange-yellow in color.  Transfer the mixture to a medium saucepan and clean the food processor.

Heat the passion fruit mixture over low heat, whisking regularly.  It will start to thicken (keep a close eye on it). Right before it starts to boil, bloom the gelatin in a small bowl by stirring in 1½ tbsp of cold water (it should only sit a minute or two).

Once the mixture boils, quickly add it to your food processor along with the gelatin and butter (be careful not to overcook the curd); blend in the food processor until it becomes shiny and smooth.  Place in an airtight container and refrigerate. (This can be made up to 1 week ahead.)

for the chocolate cookie crumbs

Set the oven to 300 degrees.  In the bowl of a stand mixer, combine the flour, cornstarch, sugar, cocoa, and salt and mix on low speed with the paddle attachment until combined.  With the mixer running, pour in the melted butter and mix until it starts to clump.

On a parchment-lined cookie sheet, spread the clumped chocolate mixture and bake for about 20 minutes.  The clumps should still be slightly moist (they will harden as they cool).  Break up any very large clumps.  Let cool and store in an airtight container. (They can be made up to 1 week ahead and stored at room temperature, or in the freezer for longer.)

for the vanilla cacao nib cake

Set the oven to 350 degrees.  Butter, line with parchment paper, and butter again three 9-inch cake pans.  In the bowl of a stand mixer, cream the butter and sugars with the paddle attachment on medium-high for 2 to 3 minutes.  Scrape down the sides with a rubber spatula and with the mixer running on low add the eggs one at a time.  Beat on medium-high for another 2 to 3 minutes.  Scrape down the sides.

On low speed, slowly pour in the milk, oil, and vanilla. Mix for 4 to 6 minutes on medium-high until the batter becomes white and almost doubles in volume.  Don’t skimp on time here.

Sift together the flour, baking powder, and salt. On low speed, add in the flour mixture until the batter just comes together.  Scrape down the sides and mix with the rubber spatula to ensure all the flour has been incorporated. 

Divide the batter among your three prepared pans.  Give each a quick whap on the countertop to help disperse the batter.  Sprinkle a heaping cup of the cacao nibs evenly among the top of the pans (reserving about ½ cup for the top of the frosted cake as a garnish).  Bake for about 30 minutes or until the cake tops turn golden and their middles are no longer jiggly (the edges should spring back slightly when gently poked). 

Cool completely on a wire rack.  Loosen each cake by running a knife along the edges and gently tapping the bottoms on the counter.  Gently invert the layers and store in the fridge wrapped in plastic wrap until ready to use. (They can be made up to 5 days in advance.)

for the coffee frosting and final assembly

In the bowl of a stand mixer, cream the butter and sugar with a paddle attachment on medium-high for 2 to 3 minutes until fluffy and pale yellow.  Meanwhile, whisk together the milk, espresso powder, and salt.

Scrape down the sides of the stand mixer and on low speed, very slowly stream in the milk mixture.  The butter will clump up a bit when this happens, so only pour a few tbsp of liquid at a time.  Don’t add more until the liquid gets fully incorporated.  Be patient.  Use immediately.

For assembly, place three small pieces of parchment paper on top of a cake plate or serving platter; they should overlap slightly (you’ll remove them after you frost the cake; they are there to help reduce your mess).  Select which cake layer you want for your bottom layer (reserve your best layer for the top) and invert so that the top of the cake is turned over on the parchment paper, and the flat smooth bottom layer is facing up. 

Using a pastry brush, spread about ½ the passion fruit syrup over the bottom layer.  Then top with a healthy dosing of the passion fruit curd.  It will slide a bit. Use your judgment on how much you’d like for the bottom layer (you’ll repeat this again with the next layer), you should have plenty to work with.  Sprinkle a thin layer of cookie crumbs over the top.  Then spread one-third of the coffee frosting on top (this won’t be easy, just do the best you can). 

Place the second layer on top of the frosting, again inverted so the smooth bottom is facing up.  Spread the remaining passion fruit syrup on top.  Add another healthy dose of passion fruit curd.  Sprinkle with cookie crumbs.  (You can also reserve some cookie crumbs for the top layer, if you wish.) Top with remaining cake layer (this can either be inverted or with the top facing right side up, your preference; inverted will be flat and more smooth while the top facing up will yield a slightly more rustic effect).

Using an offset spatula, frost the top with the remaining coffee frosting. (Dip the offset spatula occasionally in hot water to help ensure the top gets smooth.)  You can fill in the side crevices with any leftover curd and/or frosting and smooth using the spatula.  Garnish with the remaining cacao nibs.  Any leftover cookie crumbs will work well here too. Remove the parchment paper.

Transfer the cake to the freezer for an hour or so (long enough so that the layers will set).  Cover with plastic wrap and refrigerate for up to five days (or store for up to 2 weeks in the freezer).  Let the cake warm up for at least an hour before serving.

Serves 12 to 16 people

Notes:

-You can buy the passion fruit puree (see here on some tips for where to find it), but I like to make mine.  To do this, you’ll need top whirl the pulp from about 8 passion fruit in a food processor for about 15 seconds (the pulp is easily removed by slicing open the passion fruit, discard the outer shell).  Measure out 1 cup for the curd and any remaining pulp can be frozen.  In total, for this cake you’ll need about 12 to 15 passion fruit (or a little less than 2 cups passion fruit puree, divided).

-You’ll have extra of the passion fruit curd, which I did at the recommendation from Katie, of butter tree.  My favorite way to eat it was with a banana, some pineapple, and yogurt.  You won’t regret having extra, so I’ve worked a little surplus into the recipe (which I usually don't like doing, but if you are going through all this trouble you might as well enjoy the leftover bits ...).

-If you don’t have cake flour you can use 2 cups plus ½ cup plus 2 tbsp all-purpose flour and ¼ cup plus 2 tbsp cornstarch.  (The ratio is 2 tbsp cornstarch for every 1 cup flour, replacing 2 tbsp flour.)

-Everything can be made ahead of time, except for the coffee frosting.

-I’ve used whole milk with a little plain yogurt mixed in, in place of the buttermilk in a pinch.

-Have leftovers?  They can be frozen.