How to Make It
Preheat the oven to 350°. Butter an 8-inch round cake pan; line the bottom with wax paper and butter the paper. Dust the pan with flour, tapping out the excess. Melt the chocolates together in a bowl, either over a pot of simmering water or in a microwave oven.
In a food processor, pulse the amaretti with the almonds until evenly ground. Transfer the amaretti mixture to a sheet of wax paper.
Add the butter, granulated sugar and eggs to the processor and cream until satiny smooth, scraping down the sides as necessary, about 3 minutes. Add the amaretti mixture and the melted chocolate and pulse until blended.
Scrape the batter into the prepared pan and bake in the middle of the oven for 25 to 30 minutes, or until the cake domes somewhat and the top is dry and slightly cracked. Let cool on a rack for 10 minutes. Run a blunt knife between the cake and pan and unmold; peel off the wax paper and let cool right side up on the rack.