Melt the chocolate chips and set aside. Remove the can of coconut milk from the refrigerator, open it and spoon 3 tablespoons of the solid into a medium sized bowl. Add the granulated sugar and vanilla to the bowl and beat for 1 minute. Mash half the banana in a small bowl, then beat that into the whipped coconut cream. Fold in the melted chocolate. Divide filling among crusts and refrigerate for 1 hour.