Pretzel-Peanut Fudge: Omit bittersweet chocolate chips. Prepare recipe as directed, stirring in 1 cup peanut butter chips with semisweet chocolate chips. Stir in 1/2 cup coarsely crushed pretzels and 1/2 cup coarsely chopped dry-roasted peanuts along with vanilla and salt.
Cherry-Almond Fudge: Omit vanilla. Prepare recipe as directed, stirring in 1 tablespoon cherry liqueur, 1/2 cup coarsely chopped dried cherries, and 1/2 cup coarsely chopped toasted slivered almonds along with salt.
Marshmallow-Pecan Fudge: Prepare recipe as directed, substituting 1 cup (6-oz.) milk chocolate chips for bittersweet chocolate chips. Stir in 1/2 cup coarsely chopped toasted pecans and 1/2 cup miniature marshmallows along with vanilla and salt.