Here's a cake that stopped me in my tracks — and it was very specifically because it contained eggplant. I'm a big believer in eggplant's chameleon ability — after all, I've seen it transformed into jerky, bolognese, bacon, and my favorite, roses — but a cake seemed like a bit of a stretch. In The Vegetable Butcher's deft hands, though, the garden egg does indeed transform into a rustic cake, woven together with sweet polenta and the warm flavors of honey, vanilla, and nutmeg. And if you're still not intrigued, there's an orange mascarpone frosting as well.
Cara Mangini, aka The Vegetable Butcher, suggests slender Asian eggplants or small to medium Italian eggplants for this cake. And she cautions to use them as soon as you buy them. The longer eggplants sit, the more bitter they become. I quite like a finicky vegetable that tells me what it needs to be its best. Eggplant does that, and I listen — and now I listen and make this cake.
Honeyed Eggplant and Polenta Cake with Orange Mascarpone Frosting
For the eggplant purée:
4 tablespoons (1/2 stick) unsalted butter
1 pound eggplant, peeled and cut into 1/2-inch dice (about 4 cups)
1/4 teaspoon fine salt
1/4 cup water
1/4 cup honey
1 teaspoon vanilla extract
1/8 teaspoon ground nutmeg
1 teaspoon balsamic vinegar
For the polenta cake:
8 tablespoons (1 stick) unsalted butter, at room temperature, plus more for greasing the pan
1 cup all-purpose flour, plus more for dusting the pan
2/3 cup polenta
2 teaspoons baking powder
1/2 teaspoon fine salt
1 cup granulated sugar
2 large eggs, at room temperature
1 teaspoon vanilla extract
1/2 cup whole milk
For the frosting:
8 ounces mascarpone cheese, at room temperature
1 teaspoon finely grated orange zest
1/4 cup powdered sugar
1/4 teaspoon vanilla extract
Make the eggplant purée: Melt the butter in a medium saucepan over medium heat. When it begins to foam, add the eggplant and salt; turn the heat up to medium-high; and cook, stirring frequently, until the eggplant begins to soften and becomes golden on the edges, about 3 minutes.
Add the water, honey, vanilla, and nutmeg; reduce the heat to medium; and cook, stirring occasionally, until the eggplant is soft and caramelized, about 6 minutes. Add the balsamic vinegar and continue to cook, stirring frequently, until the eggplant is completely soft and a deep golden-brown, 3 to 5 minutes more.
Transfer the eggplant to a food processor fitted with the blade attachment and blend, scraping down the sides of the bowl as needed, until completely smooth. Set aside and let cool.
Make the polenta cake: Arrange a rack in the middle of the oven and heat to 350°F. Lightly butter and flour the side and bottom of a 9-inch round cake pan, making sure to shake out excess flour. (A round of parchment paper may also be used at the bottom, but be sure to butter and flour the side of the pan.)
In a medium-size bowl, whisk together the flour, polenta, baking powder, and salt to combine; set aside.
In a large bowl using a handheld electric mixer (or in the bowl of a stand mixer fitted with the paddle attachment), beat together the butter and the sugar, beginning on low speed and increasing to medium-high, until it is whipped and fluffy, about 1 minute.
Add the eggs, one at a time, whipping on medium speed after each addition. Add the vanilla and the eggplant purée, and beat until it is just incorporated. Alternately in 3 rounds, add the dry ingredients and the milk, beating well between each addition until they are just combined. Be careful not to overbeat the batter. Pour the batter into the prepared pan, using a rubber spatula to spread it evenly and smooth out the top.
Bake until the cake just starts to pull away from the pan and the top is golden-brown all over and is just firm to the touch, but still tender, 40 to 45 minutes.
Transfer the cake, still in the pan, to a wire cooling rack, and let cool for 15 minutes. Invert the cake onto the rack to release it, remove the pan, and allow the cake to cool completely.
While the cake cools, make the frosting: Place the mascarpone cheese in a large bowl and beat it with an electric mixer on medium speed (or with a whisk) until there are no more lumps (do not overmix it). Stir in the orange zest.
Sift the powdered sugar (twice if needed to ensure there are no lumps) and add it to the mascarpone slowly, beating continuously, until smooth and creamy. (If there are lumps, use the back of a spoon to make figure-eight motions, pressing the spoon against the side of the bowl.) Stir in the vanilla until just combined. Frost the top of the cooled cake and serve.
- Make ahead: The eggplant purée can be made up to 1 day in advance and stored in an airtight container in the refrigerator.
- Storage: The cake will keep, stored in an airtight container at room temperature, for 1 day.
Reprinted with permission from The Vegetable Butcher: How to Select, Prep, Slice, Dice, and Masterfully Cook Vegetables from Artichokes to Zucchini by Cara Mangini, copyright (c) 2016. Published by Workman Publishing Company.