Add bananas, coconut milk, maple syrup, vanilla, lemon juice, cinnamon and cornstarch to a blender and blend for 20-30 seconds, until smooth.
Add banana mixture to a medium sized saucepan and heat to medium high, whisking constantly. Once the mixture comes to a gentle boil, reduce the heat to medium low and simmer gently for 10-12 minutes, whisking often.
Remove the pan from heat and let cool, then transfer to refrigerator to chill for 2-3 hours, until completely cooled. Serve topped with whipped cream and vanilla wafers.