Prep your bananas: Peel, slice, and freeze them on a parchment-lined sheet for at least 2 hours or overnight. This is key for a creamy texture.
Blend the base: Add milk, protein powder, cocoa powder, nut butter, vanilla, salt, and 1 tablespoon of sweetener to your blender.
Blend until smooth.
Add the frozen bananas: Toss in the frozen banana slices. Blend on low, then gradually increase speed until thick and creamy. Use a tamper if your blender has one.
Taste and adjust: If it needs more sweetness or chocolate, add another teaspoon of sweetener or cocoa and blend again.
For a thicker shake-like texture, add a handful of ice and pulse.
Choose your finish: For soft-serve right away, fold in any add-ins and serve immediately. For scoopable ice cream, pour into a freezer-safe container.
Freeze for firmness: Freeze for 1.5–3 hours, stirring once halfway through to reduce ice crystals. Aim for a just-firm, scoopable texture.
Serve: Let it sit at room temp for 5–10 minutes before scooping if it’s very firm.
Top with a drizzle of nut butter, a sprinkle of cocoa, or a few chocolate chips.