Arrange 1 sleeve of saltines in a baking sheet so that there are no gaps. Crush remaining 1/2 sleeve and set aside. Melt butter and brown sugar in microwave until boiling.
Pour butter and brown sugar over crackers. Bake at 350 for 5 minutues or until bubbly. Remove from oven and cool 1 min. Pour chocolate chips over crackers and allow to melt. Spread with a spatula. Sprinkle with peanuts or pretzels and remaining crackers.
Refrigerate at least 30 minutes and then break up crackers into desired sizes. Can be stored in sealed container without refrigeration up to one week.