Back when I was a partner in the Total Heaven Baking Company, a wholesale baking company founded by Bill Liederman and me, having a pastry chef was still a rare phenomenon, and so this chocolate almond cake was an immediate top seller to New York City restaurants. The original recipe had called for dry breadcrumbs; I switched to fresh breadcrumbs and got a much moister cake. Like a lot of rich chocolate cakes, this one falls a little in the center while cooling and we had to trim it before pouring on the glaze. After the initial batch, we saved the trimmings and used them in later cakes in place of the breadcrumbs for an even more moist and dense result. Try it and see.
Set a rack in the middle level of the oven and preheat to 350 degrees.
Stir the almonds and breadcrumbs together and set aside. Beat the butter and 1/3 cup sugar in the bowl of an electric mixer fitted with the paddle attachment on medium speed until light, 3-4 minutes. Stop the mixer and add the cinnamon, almond extract, and chocolate. Beat on low speed to combine, then stop and scrape the bowl and beater.
Start the mixer again on low-medium speed and separate the eggs, adding the yolks to the chocolate batter as it’s mixing and transferring the whites to another mixer bowl. (If you only have 1 mixer bowl, put the whites in a small bowl and transfer the chocolate batter to a medium mixing bowl after all the yolks have been added. Wash the bowl in hot soapy water, rinse well, and dry before using for the egg whites.)
Take the bowl off the mixer and use a large rubber spatula to stir in the almond and breadcrumb mixture. Whip the egg whites on medium speed, using the whisk attachment, until they are white, opaque, and beginning to hold their shape. Increase the speed to medium-high and add the remaining 1/3 cup sugar in a slow stream, continuing to whip the egg whites until they hold a soft peak. Stir about 1/3 of the egg whites into the chocolate batter to lighten it, then fold in the rest until no streaks of white remain. Scrape the batter into the prepared pan and smooth the top.
Bake the cake until well risen but still moist in the center when tested with the point of a paring knife, 35-40 minutes. Cool in the pan for 5 minutes, then invert to a cardboard. Leave the paper on the cake and invert to a rack to cool completely.
Wait until the cake has cooled completely before preparing the glaze. Whisk the cream and corn syrup together in a small saucepan and heat just until there are a few bubbles around the edge of the liquid. Remove from heat and cool to about 100 degrees — it should feel just slightly warm when tested with a fingertip. Pour the cooled cream mixture over the melted chocolate and use a rubber spatula to stir them together to avoid creating bubbles in the glaze.
Use a long, sharp serrated knife to trim the top of the cake evenly, then place a cardboard on the cake; invert so that the smooth bottom side of the cake is upward and remove the paper. Set the cake on a rack over a pan to catch drips and pour the glaze over the cake, using a metal offset spatula to sweep excess from the top and to touch up the sides where necessary. Let stand until the glaze sets, then press the sliced almonds against the side. Transfer to a platter and cut the cake into wedges, remembering to wipe the knife with a damp cloth between cuts. Serve a spoonful of whipped cream on the side if you wish.