Step 1

In a double-boiler over medium heat, melt chocolate. Add half-and-half and Splenda; heat 5 to 6 minutes, or until Splenda is dissolved.

Step 2

Remove from heat and stir in peanut butter and vanilla until smooth. Pour into an 8-inch square baking dish; sprinkle with peanuts, if desired.

Step 3

Refrigerate 2 hours, or until firm, then cut into squares. Store in refrigerator.