The deep yellow color of the sponge is from the duck egg yolks.
It was a happy day when a friend brought me six beautiful, farm-fresh duck eggs. Having never had duck eggs before, I was very curious about them, so I immediately cooked three of them sunnyside up to check the flavor and texture. Delicious. But I had heard that they were also excellent for baking. After some searching, I discovered a recipe from Darina Allen's Forgotten Skills of Cooking: Duck-Egg Sponge Cake. The recipe was quite unusual. It called for only three ingredients (duck eggs, sugar and flour) and for the sugar to be beaten in the whites, not the yolks. How interesting! I decided to give it a try.
I loved working with the duck eggs which were a little larger than a jumbo chicken egg, with a thicker shell. The yolks were a brilliant yellow-orange and the whites beat up stiff and glossy. As you can see below, the layers came out of the oven a beautiful shade of yellow.
The most unusual thing in this recipe (besides the duck eggs) was the method for making the sponge. In this version, the eggs are separated and the whites whipped with the sugar. When they're stiff, the yolks are beaten in, followed by a gentle folding of the flour. (Usually the yolks are beaten with the sugar and the whiles are beaten separately and then folded in.)
The bottom line? This was an excellent cake. The crumb was moist and tight and the flavor rich but subtle. It worked beautifully as the cake layer for my whipped cream and strawberry cake. While each component of the cake was already stellar on it own, the combination was out of this world. I will be begging my friend for more duck eggs, that's for sure.
Ms. Allen is an Irish cook and Forgotten Skills of Cooking was first published in Great Britain. So while the recipe in the edition I was working from was converted to US measurements, there was one quirk: the pan size was listed as 7" rounds. Not too many US home kitchens will have two 7" round baking pans on hand, mine included. I considered trying one large 10" round but in the end settled on two 8" pans. The layers came out a little thinner than I would have wanted but in every other way they were a success.
I wanted a high, festive piece of cake, however, to present to a friend who was celebrating. So instead of filling the two whole layers, I cut wedges from each of the layers and built individual three layer slices. Even though I didn't have a complete cake to present to the table, this worked wonderfully.
Duck-Egg Sponge Cake with Whipped Cream and Strawberries
Two 8" layers of duck egg sponge cake (see recipe below, using 8" pans) 1/2 pint whipping cream 1 pint of strawberries, washed and thickly sliced
Whip the cream, adding sugar to taste (I did not use sugar as I found the cake sweet enough.)
Cut each sponge cake layer into six even pieces. Place a wedge on each of 4 plates. Top with a little whipped cream, followed by some strawberries and topped with a little more whipped cream. Place another wedge on top and repeat. Place a third wedge to finish and garnish with a plop of whipped cream and a strawberry.
Alternatively, do not cut the layers into wedges. Place one layer on a cake plate, top with half the whipped cream and half the strawberries. Top with the second layer and repeat. Cut into wedges and serve.
Duck-Egg Sponge Cake
Duck eggs are renowned for making a lighter, more yellow sponge cake than hen’s eggs, and are, as such, much sought after. This sponge cake is interesting because the whites, rather than the yolks, are beaten with the sugar, which is opposite to the way most sponge cakes are made. This recipe was given to me by a neighbor named Winnie Cowhig.
3⁄4 cup all-purpose flour, sifted, plus 2 teaspoons for dusting 3 organic duck eggs 6 tablespoons superfine sugar
2 x 7in round cake pans, lined
Brush the base and sides of the pan with melted butter and dust with the 2 teaspoons flour.
Separate the egg whites from the yolks. Put the whites and sugar into a bowl and whisk until stiff, preferably in an electric mixer. Whisk in the yolks one by one and then fold in the sifted flour, making sure not to deflate the mixture. Divide the mixture between the prepared pans.
Bake for 20–25 minutes. Turn out carefully and let cool on a wire rack. Sandwich together with cream and homemade jam or fresh berries. Sprinkle a little superfine sugar or confectioners’ sugar over the top and enjoy with a cup of tea.