The filling is made with coconut and pecans and this version is superb because the coconut and pecans are slightly toasted which gives it a smoky and buttery taste. Then there’s the glaze, the buttery rum glaze (yes, rum) used to coat each layer of cake before adding the coconut and pecan filling and then decadently enveloping the entire cake in a thick rich layer of chocolate icing made with Mexican chocolate, which gave it a subtle hint of cinnamon.
Butter two 9-inch cake pans, and then line the bottoms with rounds of parchment or wax paper.
Melt both chocolates together with the oil and water. Use either a double-boiler or a microwave. Stir until smooth, and then set aside until room temperature.
In the bowl of an electric mixer, or by hand, beat the butter and 1 ¼ cup of the sugar until light and fluffy, about 5 minutes. Beat in the melted chocolate, then the egg yolks, one at a time.
Sift together the flour, baking powder, baking soda, and salt.
Mix in half of the dry ingredients into the creamed butter mixture, then the buttermilk and the vanilla extract, then the rest of the dry ingredients.
In a separate metal or glass bowl, beat the egg whites until they hold soft, droopy peaks. Beat in the ¼ cup of sugar until stiff.
Fold about one-third of the egg whites into the cake batter to lighten it, and then fold in the remaining egg whites just until there’s no trace of egg white visible.
Divide the batter into the 2 prepared cake pans, smooth the tops, and bake for about 40 minutes, until a toothpick inserted into the center comes out clean.
Cool cake layers completely.
While the cakes are baking and cooling, make the filling, syrup, and icing.
Making the Filling:
Mix the cream, sugar, and egg yolks in a medium saucepan. Put the 3 ounces butter, salt, toasted coconut, and pecan pieces in a large bowl.
Heat the cream mixture and cook, stirring constantly (scraping the bottom as you stir) until the mixture begins to thicken and coats the spoon (an instant-read thermometer will read 170 degrees F.)
Pour the hot custard immediately into the pecan-coconut mixture and stir until the butter is melted. Cool completely to room temperature. (It will thicken.)
Preparing the syrup:
In a small saucepan, heat the sugar and water until the sugar has melted. Remove from heat and stir in the dark rum.
Making the Icing:
Place the 8 ounces of Mexican chopped chocolate in a bowl with the corn syrup and butter.
Heat the cream until it just begins to boil. Remove from heat and pour over the chocolate. Let stand one minute, and then stir until smooth. Add 3 cups of powdered sugar to thicken. Add one cup at a time until you get the consistency you need to frost the cake. Let sit until room temperature.
Assembling the cake:
Remove the cake layers from the pans and cut both cake layers in half horizontally, using a serrated bread knife.
Set the first cake layer on a cake plate. Brush well with syrup. Spread ¾ cup of the coconut filling over the cake layer, making sure to reach to the edges. Set another cake layer on top.
Repeat, using the syrup to brush each cake layer, then spreading ¾ cup of the coconut filling over each layer, including the final top layer.
Ice the sides with the chocolate icing, then pipe a decorative border of chocolate icing around the top, encircling the coconut topping.
Notes
If you cannot find Mexican chocolate, use regular chocolate and add some cinnamon.