Banana Layer Cake

After making several of Christina Tosi's signature creations, you'd think I'd already be prepared for what's in store and thus my jaw wouldn't drop while reading through one of her recipes.  But with this one, my jaw still dropped a bit.  There's a lot of background work that I needed to do before I could even crack an egg for the actual cake.  I don't want to give the wrong impression with how I feel about her desserts because the truth is that I have never been disappointed after first bite--and every subsequent bite for that matter.  They're astoundingly delicious.  The ingredients and flavors she's crafted just work so well.

Yes, I had to make my own feuilletine and hazelnut paste--they're those types of ingredients I imagine are only readily available in Paris--or on Amazon.  And then I had to use those ingredients to make like, a bazillion other components for the cake.  But, these desserts are a project and--in case it's not fairly evident from the subject matter on my blog--I love baking so it's not exactly a chore to have to do all of this sort of logistical work.

Plus, it's pretty easy to make your own feuilletine--and I think it's good baking experience, or--if you will--builds strong baking character. Plus, maybe you'll save a few bucks making your own.  And if you don't like doing any of that, then pretty much any ingredient is just a mouse click away.

Now the flavor of the cake is not just banana--it's extra banana.  Not only do you get the banana flavor from the actual bananas but there's an extra boost from some banana extract. And unbeknownst to myself--previous to this endeavour that is--banana extract is readily available in most supermarkets!  So that was actually an easy ingredient to retrieve.  The banana cream obviously has some excellent banana-rama kick and is as good as any banana cream you'll find in your favorite banana cream pie.

What I like so much about Christina Tosi's cakes is that--as I mentioned earlier--the ingredients really are well crafted together.  Like there's just a perfect amount of banana cream and chocolate ganache sandwiched between the cake layers.  And the "crunch" she refers to has some salt in it that offsets the sweet quite nicely.  There's different texture and taste in the cakes that seems almost perfectly balanced.

I did have a tiny issue though.  And of course it had to do with the fact that--I'm almost positive anyway--I made some of my own ingredients.  Specifically, the hazelnut paste.  I found a recipe for hazelnut paste and making it wasn't a problem.  I thought it came out right because it had the same sort of consistency that the store-bought almond paste has--pretty thick and not easily spreadable. But whatever the case, I don't think it worked too well with the last component I needed for the cake which was the hazelnut frosting.

The frosting base is just powdered sugar and butter and then essentially you just mix in the paste. But because the paste I made was more viscous than anything, it didn't form a very spreadable frosting. So, whatever Christina Tosi uses--and she actually does list her specific make and model of ingredients in the front of her book--must be a different type of paste than what I made.  In retrospect, I probably could have added more butter to make it more spreadable and that may have done the trick.  Nonetheless, I worked with what I had and in the end, I don't think it made a negative impact on the finished product.

I often think how Christina Tosi's cakes are like super-sized french entremets.  You know, those little artsy cakes that have lots of different layers and textures?  In that same sort of way, this three layer six inch cake may look simple--maybe because it's not ornately frosted or topped with some slick looking fondant--but that's just a deception.  And I can attest to that because it took me over a week to get this thing together--albeit I was working full time too.  Nevertheless, if you venture to make one of the famed Milk Bar's cakes, beware it's not something you can necessarily whip up so quickly. At the same time, after all is said and done, I'd bet money that you will not be disappointed.

Recipe

Components needed for the cake

Banana cake
55g (1/4c) milk
Chocolate hazelnut ganache
1/2 recipe of hazelnut crunch (you can just divide the recipe in half now if you don't want to make all of it)
1/2 recipe of banana cream (you can just divide the recipe in half now if you don't want to make all of it)
Hazelnut frosting

Banana cake

85g (6 T) unsalted butter at room temp.
200g (1c) granulated sugar
1 large egg
110g (1/2c) buttermilk
20g (grapeseed oil)
2g (1/2 tsp) banana extract
225g or 2 very ripe bananas
225g (1 1/3c) all purpose flour
3g (3/4 tsp) baking powder
3g (1/2 tsp) baking soda
2g (1/2 tsp) kosher salt

First, grease a quarter sheet pan and line the bottom of the pan with parchment paper.  Then, preheat the oven to 325 F.  Next, in a medium bowl combine the flour, baking powder, soda and salt and then set it aside.  And then using a small bowl, combine the buttermilk, oil and banana extract and set that aside.  Now, in the bowl of a stand mixer using the paddle attachment cream the butter and sugar together until light and fluffy on medium-high speed--about 2-3 minutes.  Scrape down the sides and bottom of the bowl and add the egg and beat for another 2-3 minutes.  Scrape down the bowl again, turn the mixer down to its lowest speed and slowly stream in the buttermilk-oil-banana extract mixture.  Then turn the mixer up to medium-high speed and beat for another 5-6 minutes or until the mixture has doubled in size and all the ingredients are fully combined and look cohesive.  Turn the mixture down to its lowest speed again and add the bananas and mix just until they have broken up and are evenly distributed within the batter.  Add the remaining dry ingredients and mix just until combined.  Pour the batter in the prepared pan and spread it evenly.  Bake the cake for about 25 minutes or until it's fully set.  Remove the cake from the oven, and let cool before removing it from the pan.

Chocolate hazelnut ganache

55g (1/4c) heavy cream
60g (2oz) gianduja chocolate chopped (I used this)
65g (1/4c) hazelnut paste (I made mine from this recipe)
38g (3 T) fudge sauce
1/2 tsp kosher salt

In a small bowl, combine all of the ingredients except for the cream.  Then, using a small saucepan, heat the heavy cream until it comes to a boil.  Next pour the cream over the rest of the ingredients and let it set for about a minute.  Then, lightly whisk until the mixture is fully homogeneous.  Store the ganache in an air tight container until ready to use.

Hazelnut crunch

110g (1/3c) hazelnut paste
80g (1/2c) hazelnut brittle
80g (1c) feuilletine (I used this recipe to make mine)
20g (2 T) confectioners sugar
3/4 tsp kosher salt

In the bowl of a stand mixer using the paddle attachment, combine all of the ingredients until everything is evenly distributed.  Store the crunch in an airtight container until ready for use.

Banana cream

225g or 2 ripe bananas
75g (1/3c) heavy cream
55g (1/4) milk
100g (1/2c) granulated sugar
25g (2 T) corn starch
1/2 tsp kosher salt
3 large egg yolks
2 gelatin sheets
40g (3 T) butter
1/2 tsp yellow food coloring
160g heavy cream
160g confectioners sugar

Using either a blender or food processor, puree the bananas, cream and milk until smooth.  Then add the sugar, corn starch, salt and eggs yolks and mix until fully incorporated.  Now, pour that mixture into a medium heavy bottomed saucepan.  Clean the food processor or blender.  After that, bloom the gelatin in cold water.  Heat the mixture in the saucepan over medium heat whisking constantly until it starts to bubble and thicken.  Once it starts to bubble let it boil for 2 minutes whisking constantly. Then pour the mixture back into the blender or food processor, add the bloomed gelatin (remember to wring out the excess water from the gelatin before adding it to the banana cream), butter and food coloring and blend until fully combined.  Pour the mixture into a heat safe bowl and chill in the refrigerator until completely cooled.  Once the banana cream is chilled, pour the remaining heavy cream and sugar into the bowl of a stand mixer.  Using the whisk attachment, whisk until medium stiff peaks have formed.  Stop the mixer, add the cold banana cream and whisk slowly until fully combined. Store the banana cream in an air-tight container in the refrigerator until ready to use.

Hazelnut frosting

25g (2 T) unsalted butter at room temp.
65g (1/4c) hazelnut paste
20g (2 T) confectioners sugar
1/8 tsp kosher salt

In the bowl of a stand mixer, cream the butter using the paddle attachment.  Add the rest of the ingredients and beat until fully smooth and fluffy.  Store in an air-tight container in the refrigerator until ready to use BUT bring to room temperature before using.

To assemble the cake

You'll need a six inch cake ring for the assembly.  First, invert the-cooled banana cake (I find that having the cake cold or even partially frozen helps with this part) onto either a silpat or a piece of parchment paper.  Using the cake ring, cut out two circles.  Clean your cake ring. Then, place the cake ring on a silpat or parchment paper lined baking sheet.  Line the inside of the cake ring with either an acetate strip that's 9-12 inches wide or--if you're like me and don't have acetate strips on hand--you can use parchment paper to do this--grant it, it's not as sturdy as the acetate but it gets the job done just fine.  For the parchment paper, just cut out a piece that will line the inside circumference of the cake ring and that is about 9-12 inches wide.  Now, place 55g or 1/4 cup of milk in small bowl and set it next to your work space.  Take the cake scraps (everything leftover from the two circles you cut out) and using your fist or some other tool you deem workable, gently mash them into an even layer at the bottom of the cake ring.  This will be your bottom layer.  Now get your milk. Using a pastry brush, brush about half of the milk onto the mashed up cake scraps at the bottom of the ring.  Then, using the back of a smallish spoon, spread half of the ganache over the cake in an even layer.  Next, spread 1/3 of the hazelnut crunch over the ganache. After that, using the back of a smallish spoon, spread half of the banana cream over the crunch as evenly as possible.  This completes the first layer.  For the second layer, place one of the cake circles you cut out over the banana cream.  And then repeat everything you did for the first layer starting with brushing the top of the cake with the remainder of the milk--spread the rest of the ganache over it, then 1/3 of the crunch and finally the remainder of the banana cream.  Your second layer is now complete.  To finish, place the remaining cake layer over the banana cream.  Spread the hazelnut frosting over the top of the cake and then sprinkle the remaining crunch over the frosting.  After that, place the cake in the freezer to set for at least 12 hours.  The day you're ready to eat the cake, take it out of the freezer, and using your thumbs pop it out of the cake ring (pushing it out from the bottom), place it on your cake platter, remove the parchment paper and let it defrost for at least 3 hours.  Then eat.