Preheat the oven to 330ºF (170ºC).
Butter or spray a 9-inch (24cm) round cake pan with removable bottom and dust with fine bread crumbs or flour.
Melt 7 ounces semisweet chocolate and 7 ounces unsalted butter together (just like you do for brownies) in the microwave (15-second spurts whisking well after each one) or over a double boiler without touching the water. Reserve.
Have the rest of the ingredients measured and ready. Separate 6 eggs: egg yolks from the egg whites, and place each in a different large clean and dry bowl.
Beat egg whites until you have stiff peaks.
With the same beaters (don’t clean them), beat egg yolks and 1 cup light brown sugar for 3-4 minutes, until light and foamy.
Fold in 1 ½ cups almond flour or ground almonds into the chocolate mixture.
Then add the chocolate mixture to the egg yolks, mixing lightly with a spatula.
Add the egg whites in 3 additions, mixing lightly with a spatula so as not to deflate them much.
Mix all trying to retain as much air as you can. It doesn't matter if it's not 100% mixed. Some streaks of chocolate here and there are ok.
Transfer to the prepared pan and bake for 35-40 minutes, until the top cracks and the surface feels quite firm. It will jiggle a bit in the center.
Let cool completely on a wire rack.
Refrigerate for 4 hours or up to 2 days, well wrapped.
Unmold carefully onto the serving platter, cover with 1 cup dulce de leche or caramel and cover with ½ cup mixed nuts.