Peel the bananas and chop them into small pieces. Place banana pieces in a freezer-safe container or a freezer bag. Freeze until solid, for at least 6 hours.
Place the frozen banana pieces, PBfit, vanilla extract, and 1/4 cup of the milk into a small food processor or a high-speed blender and pulse to break up. At first, the banana will look crumbly, but keep pulsing until you get a perfectly smooth and creamy ice cream texture with no chunks. This process can take a few minutes. If you have difficulties blending the bananas, add a splash more of the plant-based milk to help the process.
Transfer the banana ice cream to a freezer-safe container then freeze for 6 hours or overnight. When ready to serve, top with crushed chocolate cookies.
Enjoy your PBfit Peanut Butter Cookie Banana Nice Cream!