In a medium microwave safe bowl, melt butter and chocolate chips in the microwave for about a minute or until melted. Stir together until combined. Add crispy rice cereal and stir well to coat.
Press into the bottom and up the sides of a 9-inch spring form pan. You could use a pie pan but I've found that a spring form pan is much easier when it comes to removing slices. Place in the freezer to chill while you make the filling (about 10 minutes).
In a large bowl beat cream cheese until fluffy. Add the sweetened condensed milk and peanut butter and mix until thoroughly combined.
Add vanilla and lemon juice and mix until combined.
Gently fold in the whipped topping. Pour filling into the prepared crust.
Heat fudge and peanut butter in two small separate bowls for 20-30 seconds or until warm. Drizzle over filling.
Freeze for 4-6 hours or until pie is firm. Remove the cheesecake from the freezer about 10 minutes before serving to make cutting easier. Garnish with peanut butter and chocolate candy bars.