Cut bananas into small slices. Place on parchment lined sheet pan and freeze until bananas are frozen.
Puree frozen bananas in a high powered blender or food processor.
Add ~1/8tsp salt + 2-4T milk of choice for smoother blending if desired.
Blend until you achieve a soft serve texture. Don't over blend!
Fold in 1/2c cacao nibs + 1/2c chopped walnuts.
Serve immediately, or transfer to container and freeze.