Mystery Bars, Mystery Cookie, Mystery Cookies, or Easy Toffee

This is actually a recipe Grandma got from Aunt Judy, but I remember Grandma making these.

 Mystery Cookie
soda crackers
1/2 cup butter
1 cup brown sugar
1 1/2 cups chocolate chips
Place soda crackers on buttered aluminum foil that is on top of a cookie sheet.  Melt butter and sugar until it bubbles/boils.  Pour on top of crackers.  Bake 350 degrees for 5 minutes.  Sprinkle chocolate chips over the top and use a spoon to spread out the chocolate chips.  Cut and put in refrigerator.  Tastes like toffee.

 I know these as Mystery Bars, but Grandma called them Mystery Cookie on her recipe.