We’ve already established that I’m frequently overly ambitious on a rainy Sunday, and sometimes I’m just stupidly excessive. This cake is the product of one of those stupidly excessive times, or perhaps two of those times, if you count the fact that I put up the mango butter that ended up as cake filling on a similar Sunday about two months earlier.
I’d been thinking for quite a long time about combining cashews and mangoes in a cake, since mangoes and cashews are close botanical relations and natural partners the same way almonds and apricots are. It’s so logical to pair them that I was really rather surprised at the dearth of cake recipes featuring them when I went a-Googling. There seem to be a lot of cashew-mango cheesecake and upside down cake recipes, but I actually rather dislike cheesecake (shocking that there’s cake I don’t like, I know) and wanted a proper layer cake for my Sunday afternoon tea. Since I couldn’t find what I wanted, I decided to adapt the recipe for almond cake that ended up as my birthday cupcakes last year.
I was, I have to admit, a wee bit apprehensive about how the cake would turn out, given that cashews are higher in fat and waxier than almonds. I was worried they might behave weirdly in the cake and make it dense or grainy, but it turns out I had no cause for concern. The cashews melted right into the batter and the baked cake was just as wonderfully tender as it was with almonds. I even think the extra richness of the cashews might have slightly bumped up the butteriness of the cake, which, as I suspected, went beautifully with the brightness of the mango butter. To keep things really simple, I iced the cake with a very plain powdered sugar icing with just a hint of lime, and I covered the top with some more roasted, chopped cashews.
I made a huge rectangular cake because I have a largish workplace and have to make sure everyone gets their Monday treat, but you could cut all the quantities in half and make a 9-inch round cake for your tea party. Earl or Lady Grey would work especially well given the citrusy undertones of the mango butter, but any kind of tea should be lovely with this cake.
If you’re in an even more stupidly excessive mood and more inclined to fancy decorating than I ever am, I’d venture to say that this would make quite a lovely and unusual wedding or other special-occasion cake. You could even go full-bore tropical by incorporating coconut into the buttercream or fondant and surrounding the layers with white or pale yellow orchid blossoms.
Cashew Layer Cake with Mango Butter Filling
(Adapted from Rose Levy Berenbaum, The Cake Bible)
Serves a large party (at least 24)
For the cake:
1 cup roasted unsalted cashews
2 tablespoons granulated sugar
3 ⅓ cups sifted cake flour
2 cups granulated sugar
1 teaspoon baking powder
1 teaspoon baking soda
1 teaspoon fine sea salt
4 large eggs, at room temperature
1 ⅓ cup sour cream, at room temperature
2 teaspoons vanilla extract
24 tablespoons (3 sticks) unsalted butter, softened
2 cups mango butter (see notes)
2 cups powdered sugar
Juice of half a lime
2 tablespoons hot water
1 cup roasted unsalted cashews, coarsely chopped
Preheat oven to 350 F. Butter a 9 x 13 rectangular cake pan and line the bottom with parchment paper, then re-butter and flour the pan.
In a food processor, pulse 1 cup of cashews with 2 tablespoons sugar until finely ground, but be sure not to process so long it turns into cashew butter. Measure out ⅔ cup plus 1 tablespoon of the ground cashews and reserve the rest for decorating the cake.
In a large glass measuring cup, whisk together the eggs, vanilla extract, and ⅓ cup of the sour cream.
In the bowl of a standing mixer fitted with the paddle attachment, combine the flour, ⅔ cup plus 1 tablespoon ground cashews, 2 cups sugar, baking powder, baking soda and salt. Briefly mix on low to blend the dry ingredients. Add the butter and remaining sour cream and mix on low until combined, then increase the speed to medium and beat for 1 ½ minutes to lighten the batter. Scrape down the sides and add the egg mixture in 3 additions, scraping the sides and beating for 20 seconds between each one.
Spread the batter evenly in the pan, flattening the top. Bake for 45-50 minutes, until the top is lightly springy and a toothpick inserted in the middle comes out clean. Cool in the pan for 10 minutes and then invert onto a rack to cool completely, pulling off the parchment.
Once the cake is cool, split into two layers with a serrated knife. Carefully slide off the top half and spread the exposed lower half evenly with the mango butter. Replace the top half, making sure the edges line up properly, and smooth out any of the filling that dribbles out the sides.
Whisk the powdered sugar, lime juice and water in a medium bowl until a thick paste forms. Place the bowl over a saucepan of simmering water and continue whisking until the icing warms up and the sugar has dissolved completely, about 1 minute. Immediately spread the icing in a smooth layer over the top of the cake, and sprinkle first with the reserved ground cashews and then with the chopped cashews. Gently press down a bit to cement the cashews into the icing.
Let the cake sit for 15 or so minutes for the icing to firm up, and then slice with a serrated knife to serve, wiping the cake crumbs and mango filling off the knife between cuts for clean slices.
The cake should keep well for about a day at room temperature. To keep it longer, tightly wrap the filled but not iced cake in plastic and refrigerate or freeze, decorating it shortly before serving.
To make a normal-sized cake for 8-12, cut all quantities in half and bake the batter in a 9-inch round or springform pan for 35-45 minutes. It could also be divided among lined cupcake tins for about two dozen cupcakes.
If you don’t have pre-roasted cashews, spread 2 cups raw cashews on a cookie sheet and bake at 350 for 10-15 minutes, until evenly dark gold, checking often to avoid burning. Cool completely before grinding half of it with the 2 tablespoons sugar in the food processor.
I made my own mango butter shortly before I made the hurricane plum jam, because I had half a case of them getting ready to turn when I got back from a weekend trip. It would be far more sensible for you to use store-bought, but I’d suggest adding about ¼ teaspoon of ground cardamom and the juice of an orange to the butter and gently heating it until the dusty raw cardamom flavor cooks out and the extra liquid evaporates. If you’re not a mango fan, apricot or peach butter would also go quite nicely with the cashew cake and give you the same pretty color contrast.
In case you’re wondering, the reason to bother with the whole double boiler business with the powdered sugar icing is that it helps it set up quickly. If you just mixed in the liquid and poured it over the cake, it would flow right down the sides after barely covering the top, not leaving you enough structure to embed the cashews in afterward. Because it does set up VERY quickly, be sure to have the cashews at hand for pressing into the top when you start to spread the icing. If you don’t want the hassle at all, the cake is still yummy, if slightly less pretty and more mildly cashew-flavored, without the decoration.