Coffee Sauce

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.

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.

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.

Remove the pan from the heat and immediately strain the sauce through a fine mesh strainer into a metal bowl that is set into a larger bowl filled with ice water. Stir the sauce for 10 to 15 minutes, until cool. Stir in the vanilla. Remove the bowl of custard from the bowl of ice water. Cover with plastic wrap and refrigerate until ready to assemble.