Ingredients

  • 1/2 cup flour, all-purpose
  • 13 cup pastry flour, whole wheat
  • 1/4 teaspoon salt
  • 4 large eggs at room temperature
  • 23 cup sugar
  • 1 teaspoon vanilla extract
  • 1 teaspoon lime zest key lime
  • 3 tablespoons canola oil
  • 14 ounces milk, low fat, sweetened, condensed or nonfat, 1 can
  • 13 cup key lime juice
  • 1 teaspoon lime zest key lime
  • 2 tablespoons egg whites at room temperature, or equivalent dried egg whites, reconstituted according to package directions
  • 4 tablespoons sugar

Method

  • To prepare cake:
  • Preheat oven to 350F.
  • Coat two 9-inch round cake pans with cooking spray with flour, alternatively, coat the pans with regular cooking spray, line them with parchment paper and spray the paper.
  • Whisk all-purpose flour, whole-wheat flour and salt in a medium bowl.
  • Beat 4 eggs and 23 cup sugar in a large bowl with an electric mixer on medium-high speed until pale yellow and doubled in volume, 6 to 9 minutes.
  • Add in vanilla and 1 teaspoon lime zest.
  • With a rubber spatula, gently fold almond (or canola) oil into the egg mixture, using long, even strokes, until just incorporated.
  • Add the flour mixture, gently stir until just incorporated.
  • Divide the batter between the pans, spread to the edges and gently rap the pans against the counter once or twice to settle the batter.
  • Bake, rotating the pans halfway through, until lightly browned and a toothpick inserted into the center comes out clean, 20 to 22 minutes.
  • Cool on a wire rack for 10 minutes, then invert the layers onto the rack, remove the pans and parchment paper, if using, and let cool completely, about 50 minutes.
  • To prepare lime filling:
  • Mix condensed milk, lime juice and 1 teaspoon lime zest in a medium bowl until combined.
  • Refrigerate until thickened, at least 30 minutes or overnight.
  • 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.
  • 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.
  • 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.