How to Make It
In a saucepan, combine the sugar and water and stir over moderate heat until the sugar dissolves. Add the lemon slices and simmer over low heat until the syrup becomes quite thick, about 20 minutes. Let cool to room temperature. Set aside 12 of the nicest lemon slices; finely chop the rest and reserve the syrup.
Preheat the oven to 350°. Butter a 10-inch round cake pan. In a small saucepan, warm the wine. Add the apricots and soak for 30 minutes. Meanwhile, spread the almond slices on a rimmed baking sheet and toast in the oven for about 7 minutes, or until golden brown; leave the oven on. Transfer the almonds to a plate to cool. Sift the flour with the baking powder.
In a large bowl, using an electric mixer on high speed, beat the butter with the sugar until light and fluffy, about 8 minutes. Add the eggs, 1 at a time, beating well between each addition. On medium speed, gradually blend in half of the flour mixture. Add the chopped preserved lemons and the apricots with their soaking liquid and mix lightly. Gently blend in the remaining flour mixture. Using a rubber spatula, fold in the almonds.
Scrape the batter into the prepared pan, smoothing the surface. Arrange the reserved lemon slices on top and bake in the center of the oven for about 40 minutes, or until a toothpick inserted into the center comes out clean. Let the cake cool in the pan. Transfer the cake to a plate, lemons up, and generously brush the top with the reserved syrup. Using a serrated knife, carefully cut the cake into thick wedges and serve with whipped cream.