This cake has a moist texture, rich flavor and golden color, thanks to the almond flour. I paired the cake layers with Seven-Minute Frosting and unsweetened flaked coconut, which accentuate the cake's very subtle coconut flavor. This cake also is delicious with a variety of other frostings and fillings. It can be adapted an infinite number of ways and depending on the frosting, it can be dairy-free in addition to being grain-free. This recipe should be in every cook’s baking arsenal.
60 grams (2.1 ounces) unsweetened desiccated coconut flakes, for decoration
* You can use any type of frosting, filling and decoration with this cake. Among a multitude of options, this cake pairs well with chocolate frosting or a vanilla buttercream, a lemon curd or ganache filling, sprinkles or toasted sliced almond decoration.
Preheat oven to 175C (350F).
Butter a springform pan (18cm/7in) and line it with parchment paper, cut to fit. Butter the parchment paper. Place the pan on a baking sheet and set aside.
Measure all the ingredients. Sift the confectioners' sugar if needed.
In a large mixing bowl, beat the egg yolks at high speed until pale and light. Reduce the speed to moderately low and beat in rum and half of the confectioners' sugar. Turn off the mixer, scrape down the bowl, turn the mixer back on and beat on high speed until pale and thick, about 3 minutes. Reduce the speed to low and gradually add almond and coconut flours until just combined. Scrape the bowl again if needed and then set aside.
In another large (and clean) bowl, whip the egg whites, cream of tartar and salt on moderate speed until the beginning stages of soft peaks. Gradually add the remaining confectioners' sugar, one tablespoon at a time. Increase speed to moderately high and beat until the whites hold glossy, stiff peaks.
Fold the egg whites into the yolk mixture gently. Pour the batter immediately into the prepared pan and smooth out the top with an offset spatula.
Bake until the cake's top is golden brown and a toothpick inserted in the center comes out clean, about 45-50 minutes. If the top gets too golden but the cake is not yet done, tent the cake with a lightly buttered piece of aluminum foil.
Cool the cake completely, at least 1 hour. It may slightly deflate as it cools.
When ready to decorate, make the frosting as per the recipe.
When ready to assemble, take the cake out of the springform pan. Invert it onto a cutting board, remove the springform pan bottom, peel off the parchment, and slice the cake horizontally into two layers using a long, serrated bread knife (see photos).
To decorate, place a cake layer on a cake cardboard or serving plate – the top of the cake should now be the bottom. With a spatula or spoon, dollop a generous amount of frosting onto the top of the cake. Use an offset spatula to create a thick, even layer of frosting. Place the second cake layer on top. Generously apply frosting to the top and sides of the cake. Use an offset spatula to even out the top and sides, forming an even layer of frosting. Press flaked coconut (or other decoration of choice) onto the frosting on the sides of the cake.
Slice and serve.
If using Seven-Minute Frosting, the cake tastes best on the day that it is made as the frosting deflates and dries out over time; store leftovers in an airtight container in the refrigerator for up to 3 days. If using a buttercream or other frosting, the cake can stay out at room temperature and last considerably longer.