Peel 3 bananas, place in freezer ziplock bag, and put in freezer for at least 4 to 6 hours until bananas are frozen.
Meanwhile, prepare your cookie of choice! Allow cookies to completely cool prior to assembling your ice cream sandwiches.
In a quality blender, add milk and frozen bananas. Blend until smooth.
Place a sheet of wax or parchment paper on a cookie sheet. Place 6 to 8 cookies about 2 inches apart bottoms up. Scoop about 1/4 to 1/3 cup of your ice cream on the center of each. Immediately place sheet in freezer for another hour and then top with another cookie. Freeze for additional hour and enjoy!
Store in ziplock bag in freezer. For best results, enjoy the ice cream sandwiches within a week.