Slice Bananas and place in a freezer bag. Seal the bag and place it in the freezer for at least 2 hours ( or until bananas are frozen ).
Toss the bananas, along with the vanilla extract and bourbon, into either a high-powered blender ( like a Vitamix), or a food processor.
Process the bananas until their color turns from the brownish frozen banana color, to a lighter, pale color, occasionally stopping to scrape down the sides of the work bowl to make sure all bits of banana are getting processed. The bananas will start out in chunks, then slowly go to bits, then a grainy goop, and then the color will start to look lighter and creamy.
Once the light color and smooth texture is achieved, toss in the vanilla wafers, crushing them with your hands to get big chunks. Pulse the blender or food processor once or twice to get the wafers blended in.
Eat immediately ( it will be a soft frozen-yogurt consistency ) or scrape the contents of the work bowl into a freezer-frendly container and freeze for at least thirty minutes to get a firmer, more "ice cream"-like texture.