Grease a 8x8 glass dish with the margarine or oil.
In a medium sized sauce pan, melt 1/2 cup chocolate chips with 1/4 cup plant based milk over a medium heat, constantly stirring until smooth.
Once the chocolate is melted, pour into the greased baking dish, making sure to cover the bottom evenly and completely.
Place the baking dish into the freezer for 15 to 20 minutes or until it is firm.
Meanwhile, in a small mixing bowl, combine the bananas, creamy peanut butter, and vanilla extract until well combined.
Take the glass dish from the freezer and spoon the banana mixture over the chocolate, spreading evenly.
Add the remaining 1/2 cup chocolate chips with 1/4 cup plant based milk to the sauce pan used before and cook over medium heat, stirring constantly, until smooth.
Once the chocolate is melted, pour the chocolate over the top of the banana mixture, making sure to cover the banana mixture evenly.
Place the dish back into the freezer for about 2 to 3 hours.
After 2 to 3 hours, check on the firmness of the dessert, you want to be able to cut the bars before they become to hard to cut.
If they are not firm enough, return to the freezer and check in another 30 minutes or 1 hour.
Once they are firm enough to cut, cut into bars and place back into the freezer to store or serve immediately.