2. Preheat oven to 250 degrees. Line your 9"x13" baking pan with foil, leaving enough foil to hang over on all sides. Spray foil with Cooking Spray. Pour your bag of Semi Sweet Chocolate Chips evenly on the pan and place in oven for about 10 minutes or until they are almost melted. They will not melt down entirely. Using a rubber offset spatula, smooth all the chocolate around the pan evenly. Place in refrigerator for 30 minutes until set.