To make the cake, preheat the oven to 300 degrees F. In a medium saucepan, combine the 1/2 cup of sugar with 1/3 cup water and bring to a boil, stirring, over high heat. Meanwhile, combine the chocolates and the butter in a medium bowl. When the sugar mixture boils, pour it over the chocolates and stir until blended. Set aside.
In a mixing bowl, combine the 11/2 tablespoons sugar and the eggs. Using a mixer set at high speed, whip the eggs and sugar until the mixture falls back onto itself in a slowly dissolving ribbon-like pattern when the beater is lifted. Add 1/3 of the egg mixture to the chocolate mixture and fold in with a spatula to lighten. Fold in the remaining egg mixture.
Bring a kettle of water to a boil. Spray 6 (6-ounce) ramekins or 6 (2 by 3-inch) loaf pans with nonstick cooking spray and place them in a roasting pan just large enough to hold them. Divide the batter among the ramekins, place the roasting pan in the oven, and add enough water to the pan to come three-quarters of the way up the sides of the ramekins. Bake until a cake tester inserted in the middle of the cakes comes out with just a few crumbs sticking to it, about 30 minutes. Allow the cakes to cool to room temperature, about 30 minutes.
In a small saucepan, combine the chocolate and cream and heat over low heat, stirring constantly, until the chocolate is melted. Cool for at least 30 minutes.
Bring cream and almonds to a boil and store refrigerated for 24 hours. Strain, add vanilla and whip.
PLATING: Dust plates with cocoa. Invert the ramekins onto the plates and add a scoop of the almond cream to each. Drizzle the chocolate over the cake and cream, sprinkle with chocolate curls, if using, and serve.