Slice two bananas in small slices. Bring them to a large zip lock bag and space them out so they freeze individually (not lump together). Lay zip lock bag flat in the freezer and freeze for at least 6 hours (or overnight).
In a blender, bring together frozen banana slices, milk and ice cream. Blend until smooth. Add more milk if blender is stuck.
Once a thick consistency is achieved, taste and add a few more slices of bananas to bring more banana flavors if desire. Optional: set aside a few slices of banana for garnish.
Taste banana milkshake and adjust accordingly. If a thicker consistency is preferred, add more ice cream. If a thinner consistency is preferred, add more milk. If a sweeter milkshake is preferred, add more ice cream and/or bananas.
Pour banana milkshake into two (or three if you prefer smaller portions) tall glasses.
Optional: Top each glass with whipped cream, cherries and a slice of banana. Serve and enjoy!