Saltine Cracker Bars

24 saltine crackers
2/3 c. sugar
1/2 c. brown sugar
1 (heaping) c. crushed graham crackers
1/4 c. milk
1/2 c. butter
2/3 c. smooth peanut butter
1/2 c. chocolate chips
1/2 c. butterscotch chips
Grease a 9x13 pan. Assemble saltine crackers along the bottom of the pan to form a crust. In a medium saucepan, combine sugars, graham crackers, milk and butter. Stir and cook over medium heat until mixture comes to a low boil. Boil for 5 minutes, stirring constantly and then remove from heat. Carefully, pour caramel sauce over saltine crackers. Let cool. In a small saucepan, melt chocolate chips, butterscotch chips and peanut butter. Spread over caramel layer and refrigerate.