Onion cake

Chocolate cake, goat cheese mousse, and caramelized onion jam... trust me...

Last year I made a cake for the launch of a seasonal produce magazine’s (Produce Parties) Allium edition. I designed the cake to look like an allium garden, but inside, the flavors were less allium, more ode to spring. I thought, surely, no one would want an allium FLAVORED cake. I thought wrong.

I would say a good 30% of comments I got on the cake were “are there onions inside??”, which almost always were followed by looks of disappointment when I listed rhubarb, orange, bay leaf, chocolate, and olive oil as the main flavors. (they still liked it (I think)).

So, this year, when Produce Parties got invited on the local NYC news (cool alert), and I was invited to help show off a typical Produce Parties spread (it’s a magazine and a seasonal party if you are unfamiliar (get familiar)), I knew what had to be done.

So the onion cake was born. My first thought was caramelized onion jam, so I built from there. Goat cheesecake mousse would bring a nice cheeseboard vibe, and a rich, moist chocolate cake would bring everything together. Buttercream only belongs on the exterior of cakes in this kitchen, so a whisper of honey buttercream brings it all together.

And turns out, people are just as freaky as I, and so, this recipe was born.

If you really want to go the full, oniony distance and model this around a patch of dirt, I recommend baking off an extra layer of chocolate cake and crumbling it up for “dirt”, which you can adhere to the exterior of the cake. If you want the mossy look as well, crumble up any white/yellow cake and mix in matcha and a touch of cocoa powder until you reach your desired mossy green. Use sparingly, as this flavor won’t meld as well.

Chocolate cake

Turns out, sorry, I haven’t developed a good chocolate layer cake recipe. What I HAVE done, however, is sifted through a lot of them. Here are two recipes that work PERFECTLY here.

God tier chocolate cake (only the cake recipe) - Kassie Mendieta (ibakemistakes) - (paywall) this is the best chocolate layer cake recipe I have ever made. Rich, but not dense, and perfectly spongey. Exactly how I prefer my layer cakes.

Cardamom blackout cake (only the cake recipe) - Mehreen Karim - (free resource) this was my go-to layer cake recipe for YEARS. It’s moist and rich and insanely delicious. I only switched to the above because I was looking for something a bit spongier!

Caramelized onion jam

These onions are made with a caramel as the base. This did confuse a lot of people, who thought that I thought that caramelized onions are just onions mixed with caramel. I do not think that. But this process allows for a really lovely backbone of caramel-y notes to come through! For a stronger, more caramel forward flavor, use all of the sugar upfront. But beware, doing it this way will lead to quicker burning, so be on your toes!

• 700 g (3 - 5 medium) yellow onions, finely chopped

• 3 - 4 dried figs, finely chopped

• 85 g (1/3 c) sugar (divided) (plus more to taste)

• 35 g (2 1/2 tbsp) butter

• salt, to taste

• A few splashes vinegar (I like to use Tart Vinegar True Romance here, but apple cider, sherry, or any light and sweet vinegar will do)

Start by adding half of your sugar to the bottom of a large dutch oven or pan. Cook over medium heat, swirling the pan occasionally, until the sugar melts and turns amber colored. Once you hit that golden amber, add the butter to the pan and reduce to medium low. Stir the butter in carefully (it will bubble and steam) until it is nicely incorporated and you have a caramel sauce. Immediately add in your onions and a big pinch of salt. Add the chopped figs and stir well until the caramel is coating everything.

When the onions have cooked down a bit and lost some volume, add the remaining sugar. Cook over medium low - low for 1 - 3 hours, stirring occasionally and adjusting the heat as needed to prevent burning. If pieces start to stick, splash with a bit of water and continue cooking.

When they are almost done and look very caramelized, taste and add more sugar as needed. They shouldn’t taste overly sweet, but also shouldn’t leave an overwhelmingly savory onion flavor in your mouth. A touch is fine, but nothing too strong.

Once they are dark, jammy, and very caramelized, remove them from heat. Add in your vinegar and a pinch of salt to taste. Cool completely before using, and then store in the fridge.

Goat Cheesecake Mousse

Adapted from the Mascarpone Mousse recipe in More Than Cake

• 60 g (3 large) egg yolks

• 35 g (2 tbsp + 2 tsp) sugar

• pinch salt

• 1 tsp vanilla bean paste

• 2 1/2 oz (1/3 c) goat cheese

• 5 1/2 oz (2/3 c) cream cheese

• 200 g (3/4 c + 2 tbsp) heavy cream

Place a small pot with an inch or so of water to simmer. In the bowl of your stand mixer, or in a large metal or glass bowl, combine the yolks, sugar, salt, and vanilla. Whisk until combined.

Once the water is steaming, place the bowl over it, making sure the bottom isn’t touching the water. Whisk constantly until the sugar is dissolved and the mixture is warm to the touch. Remove from heat and place on your stand mixer. With the whisk attachment, or with an electric mixer, beat until it is thick, fluffy, and several shades lighter in color 3 - 5 minutes. You’ll know it’s done when you pull the whisk up and the trail of mixture creates a little pile before dissolving back into the mix (ribbon stage).

Switch to the paddle attachment (set the whisk aside - no need to clean it, just give it a good shake into the bowl) and add the goat and cream cheese. Beat on medium until fully combined with no lumps. Scrape this mix into a small bowl.

Pour the heavy cream into the bowl of the stand mixer (no need to clean in between) and use the same whisk attachment from earlier to whip until medium peaks are formed. Add the goat/cream cheese mixture to the cream and whip until the entire mixture is combined and stiff, 3-5 minutes. Use immediately or store in the fridge for up to 3 days. Re-whip before using as a filling if it deflates a bit in the fridge.

Honey Italian Meringue Buttercream

• 400 g (2 c) sugar

• 100 g (1/2 c) water

• 200 g (6 large) egg whites

• pinch of cream of tartar

• 500 g (4 1/2 sticks) butter*

• 2 tbsp honey

• salt to taste

*your butter should ideally be room temp here, but I forget a lot, and that’s okay. Just take your butter out as soon as you remember and make sure you cut it into cubes. It will still come together, it might just look weird for a second. You can also start adding the butter a few minutes earlier while the meringue is still slightly warm (just slightly warm, NOT HOT) and it will level out temp wise by the time you add all the butter. If it ends up soupy, stick it in the fridge and whip again in 30 minutes. BUT TO BE SAFE, just have room temp butter.

Add your sugar and water to a small saucepan. Cook over medium heat until it reaches 242 - 245 F. While that cooks, add your egg whites and a pinch of cream of tartar to the bowl of a stand mixer.

Once your sugar syrup reaches around 230 F, start whipping your whites on medium speed. You want the whites to reach medium peaks right around when the sugar syrup reaches 242 - 245 F. Once the syrup reaches temp, slowly and carefully pour it into the whites while the mixer is still whipping. Aim for the area in between the whisk and the edge so the hot syrup doesn’t fly up at you. Go very slowly here and pour in just a thin line, it will take some time.

Let that whip on medium high until the bowl is room temp and the meringue is thick and shiny, 15 - 20 minutes.

Once the meringue is no longer hot (slightly warm is fine, but even warm meringue will melt your butter and create a soupy mess. This can be recovered with a 30 minute chill in the fridge, but is annoying), add the butter. You can do this all at once, just make sure you don’t stick the entire stick in or it may fly up at you.

Whip for 10 -15 minutes, until thick and fluffy. It may go through crazy stages here, just beware. Add the honey and more salt to taste. Switch to the paddle attachment and beat on low until smooth, 10 -15 minutes. This will eliminate air bubbles before assembling.

To assemble

If your chocolate cake layers are tall, start by slicing off any rounded tops, and then slicing them in half.

To assemble your cake, start with a layer of cake. Pipe a tall border around the edge of the layer with buttercream to create a place for your filling. Add a thin layer caramelized onion jam, followed by a generous layer of goat cheesecake mousse. Repeat the process with as many layers as you desire. Coat the entire thing in honey buttercream, and decorate! You now have an onion cake.