Drain the cottage cheese (optional but helpful): If your cottage cheese seems very wet, set it in a fine-mesh strainer for 5–10 minutes.
This step helps achieve a thicker, creamier mousse.
Add ingredients to blender: Place cottage cheese, cocoa powder, sweetener, vanilla, and salt in a high-speed blender or food processor. If using, add the cooled melted dark chocolate.
Blend until silky: Start on low, then increase to high. Blend 30–60 seconds, pausing to scrape the sides as needed.
If it’s too thick to blend smoothly, add milk 1 teaspoon at a time until the texture moves easily.
Taste and adjust: Check sweetness and chocolate intensity. Add a bit more sweetener or cocoa if needed. Blend again for a few seconds to combine.
Chill: Spoon into serving cups or a storage container.
Cover and chill at least 30–60 minutes. The mousse thickens and the flavors deepen as it rests.
Serve: Top with berries, shaved chocolate, or a light sprinkle of sea salt. Enjoy cold.