Place chocolate morsels and butter in a heavy saucepan. Cook over low heat until chocolate and butter melt, stirring often. Gradually whisk in cream. Cook, stirring constantly, 2 to 3 minutes or until smooth. Remove from heat; stir in coffee. Serve slightly warm.
Note: Scooped into an attractive jar, leftover Heavenly Fudge Sauce makes a great gift for chocolate-lovers. It's good on other desserts, too.