Preheat oven to 350°F. Line a 13"x 9" pan with non-stick aluminum foil, allowing it to extend over edges of pan.
Melt together butter and peanut butter for the crust.
Combine crushed cookies and peanut butter and butter mixture. If the crust is too moist add graham cracker crumbs as necessary up to 1/2 cup. Press mixture into bottom of prepared pan. Bake for 4-6 minutes.
Set aside to cool.
Combine condensed milk, peanut butter, and vanilla, stirring until smooth.
Fold in mini chocolate chips. Set aside.
Heat caramel ice cream topping in the microwave for about 30 seconds to soften it slightly.
Sprinkle chopped candy bars over prepared crust.
Drizzle caramel over toppings.
Carefully spoon the sweetened condensed milk mixture over the caramel and toppings. Gently spread it to the edges of the pan so all of the caramel is covered.
Bake for 25-27 minutes or until lightly browned. Cool in pan on wire rack. Using foil, lift out of pan. Peel foil away, and cut into 2 - 3 inch bars.