Light Mocha Pie
["1/3 c. hot water", "1/2 (19.85 oz.) box light fudge brownie mix (about 2 c.)", "2 tsp. vanilla extract, divided", "2 egg whites", "vegetable cooking spray", "3/4 c. skim milk", "1 (3.9 oz.) pkg. chocolate flavored instant pudding or pie filling mix", "1 1/2 c. reduced calorie whipped topping, thawed", "chocolate chips (optional)"]
["Combine hot water, brownie mix, 1 teaspoon vanilla and egg whites; stir until blended well.", "Pour into a 9-inch pie plate coated with cooking spray.", "Bake at 325\u00b0 for 22 minutes.", "Let crust cool completely."]
["water", "light fudge brownie mix", "vanilla", "egg whites", "vegetable cooking spray", "milk", "chocolate", "chocolate chips"]