Whisk all ingredients, minus banana and whipped topping, together on stove top
Cook over medium heat for 6-8 minutes until thickened
Pour into individual cups or one glass bowl, cover and refrigerate until cool (2-4 hours)
To make parfaits layer with crushed nilla wafers, homemade cool whip, and banana coins
For cool whip place ingredients in a chilled mixing bowl and mix with a hand mixer until fluffy. Place in fridge to thicken up then ready for use!