Lay the banana slices on the prepared baking sheet. Place the baking sheet in the freezer. Freeze the sliced bananas for 1 hour.
Remove the frozen banana slices from the freezer.
Add ½ of the frozen slices to either a food processor or a blender.
Pulse the frozen bananas 5 to 7 times, then purée for 2½ to 3 minutes. The ice cream mixture will go from very lumpy to finally a soft-serve ice cream consistency. Spoon the mixture into a loaf pan. Blend the remaining frozen bananas. Cover pan with plastic wrap and place back in the freezer for 1½ to 2 hours until firmly set. Scoop and serve.