Almond Apricot Cake

Heat oven to 350 degrees F. Coat two 9-inch round cake pans with cooking spray. Line the bottoms with parchment paper; spray the paper. In a food processor, process 8 oz (2 1 ⁄2 cups) almonds and the cake meal until finely ground. On a baking sheet, lightly toast the remaining almonds; set aside. Using an electric mixer, beat the egg yolks to combine. Gradually beat in 1 cup sugar until combined. Increase speed and beat until the batter leaves a trail for 5 seconds, 4 to 5 minutes. Beat in the orange and lemon zests and extract. In three additions, fold in the nut mixture until fully incorporated. Using an electric mixer and a clean, dry bowl, beat the egg whites with the salt until foamy. Increase speed until soft peaks form. Gradually add 2 tablespoons sugar and beat until stiff (but not dry) peaks form. Stir half the whites into the yolk mixture, then fold in the remaining whites until no streaks remain (be careful not to over-fold). Divide the batter between the pans. Bake until a pick inserted into the center comes out dry, 23 to 25 minutes. Let the cakes cool completely in the pans. Meanwhile, place the apricots in a small saucepan. Add the lemon juice and remaining 2 tablespoons sugar. Cover with water (about 2 cups) and bring to a boil. Reduce heat and simmer until the apricots are plump and nearly all of the liquid has evaporated, about 20 minutes. Transfer the mixture to a food processor and purée until smooth. Invert one cake layer on to a serving platter. Spread 3 ⁄4 cup apricot purée on top, then sandwich with the remaining layer. Spread the remaining apricot mixture (about 1 1 ⁄4 cups) on the top and sides. Press the sliced almonds on the sides of the cake. Serve with whipped cream (if using).