Place thawed whipped topping in a bowl. Microwave peanut butter 20-30 seconds, until melted. Gently stir peanut butter into whipped topping.
Microwave hot fudge 10-20 seconds until melted. Stir into peanut butter topping.
Unwrap 6 ice cream sandwiches and arrange them in the bottom of an 8x8 dish (you will have half of an ice cream sandwich left over). Spread half the peanut butter topping over the ice cream sandwiches.
Repeat with the remaining ice cream sandwiches and peanut butter topping.
Cover dish with plastic wrap and freeze at least 4 hours or until firm.
Before serving, top with additional hot fudge, Reese's pieces, and peanuts if desired.