Blend the base: Add milk, cottage cheese, protein powder, sweetener, vanilla, pudding mix, salt, and any optional fat to a high-speed blender. Blend until completely smooth and glossy, 30–60 seconds.
Taste and adjust sweetness.
Chill the mixture: Pour into a bowl, cover, and refrigerate 30–60 minutes. This helps the pudding mix hydrate and improves texture.
Freeze shallow: Transfer to a shallow freezer-safe container (metal loaf pan or wide glass dish works best). Spread evenly for a thin layer.
Stir as it sets: Freeze for 2–3 hours, stirring with a fork every 30–45 minutes to break up ice crystals.
Scrape the edges into the center each time.
Scoop and serve: When thick and scoopable like soft serve, enjoy right away. For firmer scoops, freeze an additional 1–2 hours, then let it sit at room temp 5–10 minutes before scooping.