So, do they work? First, a note: when trying out a new cake recipe, first make sure that it isn't missing any key ingredients like, oh, say LEAVENERS. Secondly, don't proceed to look at your two pans full of essentially flour and egg whites then put them in the oven with a shrug, fully knowing that this is probably not going to turn out well. Witness: the resulting ultimate cake fail, aka key lime crepes.
Luckily I had enough ingredients for a new recipe attempt and the resulting Key Lime Meringue Cake was awesome. While the cake baked at a slant, rather than perfectly flat, it did avoid the typical domed top and was extremely moist and spongy with evenly-cooked edges. I'm not sure the $8.99 price tag for two strips was really worth it, but I'll have to bake a few more cakes before my final verdict.
adapted from Eating Well
1/3 cup low-fat milk
3/4 cup plus 2 tablespoons unsifted cake flour
1 teaspoon baking powder
1/4 teaspoon freshly grated nutmeg
2 large eggs, at room temperature
2 large egg whites, at room temperature
1 cup sugar
2 teaspoons fresh or bottled Key lime juice
2 teaspoons vanilla extract
1 14-ounce can nonfat sweetened condensed milk
1/3 cup lime juice, preferably Key lime
1 teaspoon freshly grated lime zest, preferably Key lime
2 large egg whites, at room temperature, or equivalent dried egg whites, reconstituted according to package directions
1/4 cup sugar
1. Preheat oven to 350°F. Coat a 9-inch round cake pan with cooking spray with flour; alternatively, coat the pan with regular cooking spray, line them with parchment paper and spray the paper.
2. Heat milk in a small pan until steaming; remove from the heat, cover and set aside. Sift flour, baking powder and nutmeg into a bowl; set aside.
3. Beat 2 eggs and 2 egg whites in a mixing bowl with an electric mixer on low speed until frothy. Add 1 cup sugar and beat on medium speed until the eggs are very fluffy and pale, a full 3 1/2 minutes. Add 2 teaspoons lime juice, vanilla and the reserved dry ingredients. Beat on low speed just until the flour is incorporated. Beat in the hot milk (the batter will be thin).
4. Pour the batter into the prepared pan. Bake until the top feels firm when touched lightly and a skewer inserted in the center of the cake comes out clean, 23 to 25 minutes. Let the cake cool in the pan for 5 minutes. Run a knife around the inside of the pan to loosen the edges. Turn the cake out of the pan and set it right-side up on a wire rack to cool completely. When cooled, use a long serrated knife to slice the cake horizontally into two layers.
5. To prepare lime filling: Whisk condensed milk, lime juice and 1 teaspoon lime zest in a medium bowl until combined. Refrigerate until thickened, at least 30 minutes or overnight.
6. To prepare meringue: Beat egg whites in a medium bowl with an electric mixer at high speed until soft peaks form. Beat in 1/4 cup sugar in a slow, steady stream. Continue beating until stiff peaks form.
7. Position oven rack about 6 inches from the heat source; preheat broiler. Transfer one layer, bottom-side down, to a large baking sheet. Spread the meringue on top of the cake, creating decorative peaks and valleys in the meringue with a rubber spatula. Broil until lightly browned, watching carefully to prevent burning, 30 seconds to 1 minute.
8.To assemble cake: Place the plain layer, top-side down, on a serving plate; spread the lime filling on top. Cover with the meringue-topped layer.