Chocolate Beetroot-Kale Cake with Vanilla Buttercream
Photo by Michael Piazza / Styled by Catrine Kelty
Yes, you read that title correctly. There are beets and kale in this chocolate cake. Why would anyone put kale into a cake, you’re asking? Well, hear me out.
I have a picky kid. A boy who will not eat a fresh strawberry, or a cooked bean, or a leaf of lettuce. He will not eat my roasted chicken (see last month’s column) unless it is bathed in ketchup. He will only eat tomatoes in sauce form, completely pureed, with no chunks; forget about raw tomatoes. Or oranges. Or grapes. No tuna fish, no shrimp, no seafood of any kind unless it is deep fried, doused in ketchup.
His palate is limited. Rice, potatoes, pasta, burgers, ham and cheese sandwiches, pizza. Pretty basic, and not really all that nutritious, aside from the apple slices and frozen peas I force on him, and the occasional avocado wedge topping a taco.
So when he agreed to drink a green smoothie every morning, full of kale and spinach, but tasting just like the frozen banana, mango and cocoa powder that round out the ingredient list, I was shocked—and overjoyed. Fruits and veggies go into him first thing in the morning without complaint, and I don’t have to fret when the green things on his dinner plate get pushed around and ignored later on. We’re trying to make mealtime more about conversation and togetherness, and less about how much or how little everyone is eating. (Our second child is as adventurous an eater as the first one is picky; she’ll eat anything and everything.) It’s a struggle, but we’re getting there. And the fact that he’d drink something green as long as he couldn’t taste what made it green? It was a real breakthrough.
This got me thinking: Could I put pureed kale and other vegetables into otherwise rich and chocolaty baked goods, his all-time favorite desserts, and expect him to eat them? I’d been trying to make a really delicious chocolate kale cake for a few years, just for fun, and usually ended up with something almost tasty, almost dessert-quality, but there was always something vaguely sulfuric about the result. The finely chopped kale was never broken down enough to simply disappear into the chocolate the way I wanted it to, and there was a lingering vegetal aftertaste that just wasn’t very appealing.
Enter the high-powered blender, and the beetroot. I’d seen recipes all over the internet for chocolate beet cakes, usually using the beet puree as a substitute for some or all of the fat in a recipe, or in place of eggs to make it vegan. This was not my intent: Fat and eggs are good in cakes, so I planned to keep them in, but the idea still intrigued me. Could this be a red-velvet cake without the entire bottle of red food coloring? And, if beets are pureed in a high-tech blender to a smooth, crimson paste, would a few leaves of kale get noticed if they somehow ended up in the mix? I gave it a try, riffing off of a classic sour cream-chocolate cake recipe and adding a pinch of cinnamon, which enhances anything chocolaty, in my opinion.
The result is a dense, richly flavored, almost black chocolate cake (so much for the red velvet, but that’ll be an experiment for another day). Frosted with a classic vanilla buttercream, this cake is certainly dessert-worthy, and has no lingering vegetal flavor at all. Instead it boasts an earthy richness not found in other chocolate cakes. My family loved it and asked for more, even after being informed of its secret ingredients. The picky eater even wanted it in his lunchbox in lieu of his usual ham and cheese, because, “It’s basically health food, Mom!”
I suppose you could make this cake even healthier by substituting whole wheat flour for some of the white flour, but hey, baby steps. There’s kale in this dessert. And it’s delicious.
4 medium beets (about ¾ pound), scrubbed and roasted until tender, about 1 hour
5 large leaves Tuscan kale, stems removed, greens coarsely chopped
½ cup water, divided
2 cups organic all-purpose flour
½ cup cocoa powder
2 teaspoons baking soda
1 teaspoon salt ½ teaspoon cinnamon
1 3-ounce bar 80% dark Taza stone-ground chocolate, broken into small pieces
1 stick cold unsalted butter, cubed
1½ cups organic cane sugar
1 teaspoon pure vanilla extract
3 large eggs
4 tablespoons Vermont Creamery crème fraiche
2 sticks organic unsalted butter, at room temperature
2 cups organic powdered cane sugar, sifted
½ teaspoon sea salt
1 teaspoon pure vanilla extract
Preheat the oven to 350°F. Prepare one 9”x2” cake pan by buttering it, laying a round of parchment on the bottom, buttering again, and “flouring” it with a spoonful of cocoa powder, shaking it around to distribute evenly and tapping out the excess. Set aside.
Peel the roasted beets, quarter them, and add them to a high-powered blender (a Vitamix or similar, but a standard blender should do the trick, too; just blend for a minute or so longer to really get a smooth puree). Add the chopped kale and ¼ cup water; blend, adding an additional ¼ cup water if needed. Blend long enough to get a perfectly smooth puree. You should end up with about 1½ cups of beet-kale puree.
In a double boiler or bowl set over simmering water on the stove, melt the chocolate and whisk in the butter, cube by cube, until incorporated. Remove from the heat and set aside to cool down; stir in the vanilla.
In a mixing bowl sift the flour, cocoa, baking soda, salt, and cinnamon together and set aside. Beat the eggs and sugar in a standing mixer with the paddle attachment until fluffy and very pale yellow, then add the beet-kale puree and stir to combine. Add the cooled chocolate; beat again, scraping down the sides of the bowl.
Add the dry ingredients to the wet in four parts, alternating with 1 tablespoon crème fraiche as you go. Mix just to combine each time, scraping down the bowl between additions. When all ingredients are incorporated, pour the batter into the prepared pan and bake 60-70 minutes, or until a cake tester inserted into the middle of the cake comes out clean. Set aside to cool while you make the buttercream.
Rinse your mixer bowl and paddle attachment and reassemble them. Beat the two sticks of room temperature butter until very light and fluffy, scraping down the sides of the bowl a few times. Add the sifted powdered sugar in 2-3 parts so as not to send sugar dust all over your kitchen, then add the salt and vanilla and keep beating another 1-2 minutes or until smooth, fluffy, and increased in volume by about half.
Run a knife around the edge of the cake and turn it out onto a plate, then remove the parchment and flip it over again onto a serving platter or cake stand so the domed top is facing up. Fit some parchment scraps around the bottom of the plate for clean frosting, then spread the buttercream over the whole cake with an offset spatula. Remove the parchment pieces and serve.
Note #1: If you’re ambitious and have a pink lover in your house, save the skins from the roasted beets and submerge them in just a little bit of water. Add a teaspoon or so of this fuchsia liquid to the buttercream as you’re beating it to make a beautiful pink frosting. Add more to deepen the color, if you wish, but no more than 1 tablespoon.
Note #2: Unfrosted, this makes a great countertop snacking cake. The flavors really develop with age, and a little slice here and there makes a perfect accompaniment to coffee or tea, or even with a glass of sherry after dinner.
This recipe appeared in the Winter 2015 issue.