1. Line 9-inch square pan with foil, extending over sides. Rub with butter.
2. Combine evaporated milk, sugar, butter and salt in 2-quart microwave-safe bowl. Microwave on high power for 6 to 8 minutes or until mixture comes to rolling boil, stirring twice.
3. Add marshmallow creme and chocolate chips to butter mixture; blend until smooth. Stir in pecans, vanilla and bourbon, if desired. Pour into prepared pan. Cool to room temperature. Using tip of knife, mark fudge into 36 squares. Refrigerate until firm.
4. Lift foil and fudge from pan. Remove foil from sides. Cut through lines to make 36 pieces. Store in refrigerator.Stovetop method:
5. Line and butter pan as above. Combine milk, sugar, butter and salt in large saucepan. Bring to boiling over medium heat, stirring; boil for 5 minutes, stirring constantly. Remove from heat. Add remaining ingredients. Proceed as above.