Prep the bananas: Peel and slice bananas into coins about 1/2 inch thick.
Spread them on a parchment-lined tray so they don’t clump.
Freeze solid: Freeze at least 2–3 hours, or until firm. For best texture, freeze overnight.
Set up the blender: Add frozen banana slices to a high-speed blender or food processor. Let them sit for 2–3 minutes to soften slightly.
Add flavor: Pour in vanilla and a pinch of salt.
If using cocoa or nut butter, add it now.
Blend patiently: Pulse, then blend, scraping down the sides as needed. Add milk 1 tablespoon at a time only if the blades struggle. Keep going until completely smooth and creamy.
Adjust and taste: Taste and tweak.
More vanilla, a dash of cinnamon, or another spoon of nut butter can round out the flavor.
Serve soft-serve style: Eat immediately for a soft, silky texture. Fold in chocolate chips or nuts by hand if desired.
For scoopable ice cream: Transfer to a loaf pan, cover, and freeze 1–2 hours. Let sit on the counter 5–10 minutes before scooping.