Make the Brazil nut cocoa biscuit: 1. Position a rack in the center of the oven and preheat to 350 degrees F. Spread the Brazil nuts in a single layer on a baking sheet and roast for 10 minutes. Transfer the nuts to a large kitchen towel and rub briskly to remove most of the skins. Open the towel and spread out the nuts to cool. Select 8 of the most attractive nuts to reserve for garnish. 2. Line the base of a 9-inch springform pan with foil. Assemble the pan and lightly butter and flour the bottom and sides of the pan, shaking out the excess. 3. In a food processor fitted with the metal chopping blade, combine the toasted Brazil nuts and 1/4 cup of the sugar. Process for 30 to 45 seconds, until finely ground. Add the flour, cocoa, and baking powder, and process 20 seconds until well blended. 4. In the 4l/2-quart bowl of a heavy-duty electric mixer using the whip attachment, beat the egg yolks with 1/4 cup of the sugar at medium-high speed for about 5 minutes until it is pale yellow in color and forms a ribbon when the whip is lifted. 5. In another 4/-quart bowl, using a clean wire whip attachment, whip the whites until soft peaks form. Gradually add the remaining 1/4 cup sugar and whip until stiff and shiny. 6. Sprinkle one-third of the nut mixture over the yolk mixture and fold in gently using a rubber spatula. Add one-third of the whites and gently fold in. Repeat until all the nut mixture and whites are incorporated. Gently fold in the melted butter. 7. Scrape the batter into the prepared pan and spread evenly with a spatula. Bake for 33 to 38 minutes until a wooden toothpick inserted in the center of the biscuit comes out clean. Cool the cake in the pan on a rack for 20 minutes. Run a thin-bladed knife around the edge of the biscuit to loosen it from the side of the pan. Turn the cake over onto the rack and remove the side and base from the pan. Carefully peel off the foil. Cool the cake completely on a wire rack. Make the coffee sauce: 1. In a heavy, medium saucepan, combine the crushed coffee beans, half-and-half and 1/4 cup of the sugar and bring to a gentle boil over medium heat. Remove from the heat and let steep 5 minutes. 2. In a medium bowl, whisk the yolks with the remaining 1/4 cup sugar until blended. Gradually whisk the hot half-and-half mixture into the yolk mixture. Return this mixture to the saucepan. 3. Continue cooking the mixture over medium-low heat, stirring constantly with a wooden spatula for 3 to 5 minutes, or until the sauce has thickened slightly. Do not boil. It is done when you can run your finger down the back of the spatula and a path remains in the sauce for several seconds. continued in part 2