So this only involves the best ingredients ever, and y’all, thank goodness it’s so rich, because I desperately wanted to eat the whole thing and yet managed to restrain myself. Chocolate and Valentine’s Day will always go hand-in-hand to me, but there’s obviously no need to restrict this to one day a year: Nutella cake is appropriate for any day, in my book. To the kitchen!
adapted from How To Be A Domestic Goddess by Nigella Lawson
For the cake:
6 large eggs, separated, at room temperature
pinch of salt
1/2 cup (4 oz./1 stick) unsalted butter, room temperature
1 13-oz. jar Nutella (or other chocolate-hazelnut spread), room temperature
1 tbsp. Frangelico (hazelnut liqueur), rum, or water
scan 1/2 cup ground blanched hazelnuts
4 oz. bittersweet or semisweet chocolate, chopped, melted, and cooled slightly
For the ganache:
4 oz. blanched hazelnuts, lightly toasted and cooled
1/2 cup heavy cream
1 tbsp. Frangelico, rum, or water
4 oz. bittersweet or semisweet chocolate, chopped
For the totally-unnecessary-but-also-fun chocolate topping:
3-4 oz. high-quality bittersweet or semisweet chocolate, chopped (I can’t remember if I’ve said this on the blog before, but in general you don’t want to substitute chocolate chips for actual baking chocolate in most recipes. Chocolate chips have added ingredients in them to help them keep their shape, so they should really only be used when you need actual chocolate chips. Or a snack).
1 chocolate transfer sheet, cut to about 9 x 12 inches
(these are clear sheets with designs “printed” on them in cocoa butter. When you pour melted chocolate over the designs, the cocoa butter melts and transfers the design to the chocolate. Once the chocolate hardens, you simply peel the transfer sheet off, leaving the design behind. I used hearts, because duh, but there are also gold squiggles and white damask and cheetah print and lots of other fun options! My transfer sheets are a little old, so the design transferred imperfectly, but yours will be wonderful and glorious).
Before you begin, you’re gonna want to skin your hazelnuts. The instructions I’ve always read and tried dutifully to follow in the past involve roasting, steaming, and rubbing the hazelnuts in a kitchen towel to remove the skins, with the result that your entire kitchen is covered in bouncing partially-skinned hot hazelnuts and there are little flakes of hazelnut skin all over everything and you want to scream. This time around I followed the instructions in this post, and I strongly encourage you to do the same, because while it’s still a little fussy and time-consuming, it’s a MUCH MORE PLEASANT EXPERIENCE. Blanching FTW.
To make the cake:
Preheat the oven to 350 degrees Fahrenheit. Line the bottom of a 9″ x 3″ springform cake pan with parchment paper, then butter the parchment paper and the sides of the pan.
Combine the egg whites and salt in the bowl of an electric mixer fitted with a whisk attachment. Mix on low speed for 2 minutes, then increase speed to medium and whisk until egg whites are stiff but not dry. In a separate bowl, beat the butter and Nutella together on medium speed until fully combined, about 90 seconds, then add the Frangelico (or rum or water), egg yolks, and ground hazelnuts. Beat for 2 more minutes on medium speed, stopping once to scrape down the sides of the bowl with a spatula.
Add a generous dollop of beaten egg whites to the chocolate mixture and beat on low speed to lighten the batter. Remove the bowl from the stand mixer and gently fold in the egg whites, a third at a time. Pour the batter into the prepared pan and bake for 35-40 minutes, until the top is set and the cake is just beginning to pull away from the sides of the pan. Cool completely at room temperature. [Note: both times I made this, the cake puffed up nice and tall and then collapsed slightly in the middle as it cooled. Even though Nigella didn’t mention it specifically, I think that’s supposed to happen? Fellow bakers, weigh in.]
To make the ganache:
In a small saucepan, heat about an inch of water over medium-low heat until it simmers, then place a double boiler on top. Combine the cream, Frangelico (or rum or water) and chopped chocolate in the double boiler, and heat until the chocolate is melted and the mixture is smooth, stirring frequently. Transfer the ganache to a medium bowl and whisk vigorously until it’s cooled and slightly thickened, about 8-10 minutes.
Run a knife around the sides of the cake pan and then carefully remove the outer ring. Nigella advises leaving the cake on the bottom of the springform pan, as it’s a damp and fragile cake, but I used that weird cake-level-lifter thingie I bought when I made a wedding cake and it actually did a good job transferring the cake to my glass cake plate, so money well-spent after all?
Anyhoodle, pour the ganache over the top of the cake and spread it to the edges using an offset spatula. Roughly chop the 4 oz. blanched and toasted hazelnuts, then sprinkle over the top of the cake in a manner you see fit. Top with the totally-unnecessary-topping, should you so choose.
For the totally-unnecessary topping:
Place your transfer sheet on a flat surface (like a tea-tray or baking sheet), design facing up. I did NOT temper the chocolate for this project, as I didn’t want the circles to shatter when I cut them out, but if your chocolatier skills are more refined than mine, then you do you. Melt about 3-4 oz. chopped bittersweet or semi-sweet chocolate (Scharffen-Berger or Valrhona or Callebaut would be particularly fancy/delicious here) in the microwave or in a double boiler, heating until the chocolate is just barely hot and stirring to melt the last few little bits. Using an offset spatula, spread the chocolate over the transfer sheet in a very thin layer and transfer the tray/baking sheet to the fridge. Chill until the chocolate is fully set. I used a metal biscuit cutter that I ran under hot water to warm up to cut out my circles, but again, if you are into fancy chocolatier stuff I have no doubt that there are tools and such out there to help with the cutting-out process. Regardless, cut out your circles (or hearts or stars or what have you) and carefully peel off the transfer sheet backing. Gently press the edges of the circles into your cake, being careful to handle only by the edges so as to avoid fingerprints (this is a do-as-I-say-and-not-as-I-do pro tip).