Remove one dollop of whipped topping and place into a small piping bag fitted with a 1M tip. Cover and refrigerate.
16 oz whipped topping
Mix together pudding, sour cream, and remaining whipped topping. Place into a piping bag. You may need to put the mixture into two bags.
3.4 oz Vanilla Instant Pudding, 1 cup sour cream
Use a knife to spread a thin amount of filling onto the bottom of a whole graham cracker.
14.4 oz graham crackers
Place 4 graham crackers into a rectangle or square shape onto a serving platter, gently press the "frosted side" down onto the plate so it sticks. Pipe filling onto the graham crackers.
Top with thin sliced strawberries and bananas. Repeat this five more times, ending with filling but not fruit.
4 banana, 1 quart strawberries
Cover and refrigerate overnight.
The next day, uncover and pipe remaining whipped topping onto the cake in small areas. Top with sliced strawberries and bananas and serve immediately.