If your bananas are soft enough, just mix all the ingredients together with a mixer, for around two minutes.
Pour into a greased and floured 9x13 inch baking dish,
and bake in a preheated 350 degree oven for around 30 -35 minutes,
or until the cake will spring back when you touch the middle of it.
While the cake is cooling, you can make the frosting.
First mix together the milk, pudding and powdered sugar with your mixer,
then fold in the whipped topping.
When the cake is completely cool, top with the "frosting," and refrigerate until you're ready to serve.