In heave saucepan over low heat, melt chocolate and butter. Combine whipping cream and vanilla; gradually blend into chocolate mixture. Stir in 1/2 cup chopped peanuts. Carefully place pan in a shallow bowl of ice water: form chocolate mixture into 24 small balls; roll each in finely chopped peanuts or cocoa powder. Or, to chocolate coat, refrigerate balls until chilled then Dip balls, one at at time in melted chocolate, turning to coat sides. Place on waxed paper. Let stand until chocolate is set.
Yield: 12 servings (2 truffles per serving)