Chocolate Mayonnaise Sheet Cake
["3 c. flour", "1 1/2 c. sugar", "3 tsp. baking soda", "6 Tbsp. Baker's cocoa", "3/4 c. salad dressing or mayonnaise", "2 tsp. vanilla", "1 1/2 c. cold water"]
["Mix first 4 ingredients.", "Add salad dressing and vanilla.", "Add water.", "Bake at 350\u00b0 for 25 to 30 minutes."]
["flour", "sugar", "baking soda", "cocoa", "salad dressing", "vanilla", "cold water"]