Pour into a saucepan and cook over medium high heat and stir fairly consistently until thickened.This will take about 20 minutes.
You will want to watch over it and stir often so the mixture doesn't stick to the bottom of the pan and burn.
While your pudding is cooking, you will want to crush vanilla wafers and add a small layer to each of your small jars. I did this close by the stove, so I could continue to stir the pudding mixture.
After your pudding mixture is thickened, you will want to let it cool a bit. Then, add a small amount on top of the layer of vanilla wafers in your jars.
Top this layer with chopped up bananas, then repeat the process once more.
When you are ready to serve your banana pudding jars, top each one with whipped cream and a banana slice for garnish.
Notes
You can store the banana pudding jars in the fridge until ready to serve.Top with the whipped cream right before serving.