Drain if watery: If your cottage cheese looks loose or watery, tip it into a fine-mesh strainer for about 5 minutes to let the excess liquid run off. This keeps the finished mousse thick instead of runny.
Measure ingredients: Measure out the peanut butter, honey, vanilla extract and salt so everything is ready to go straight into the blender.
Load the blender: Add the drained cottage cheese, peanut butter, honey, vanilla and salt to a blender or food processor.
Blend until smooth: Blend on high for 30 to 45 seconds, stopping once to scrape down the sides, until the mixture turns pale tan and glossy with no visible curds.
Thin if needed: If the mousse is thick enough to hold a spoon upright, add milk one tablespoon at a time and blend again until it falls softly off a spoon.
Taste and adjust: Taste the mousse and blend in an extra teaspoon of honey if you prefer it sweeter, or an extra pinch of salt to balance the peanut butter.
Chill or serve soft: Spoon the mousse into bowls and refrigerate for 10 to 15 minutes for a firmer bite, or serve it right away while it's still soft and pudding-like.
Add toppings: Finish with mini chocolate chips, a dusting of ground cinnamon, or chopped peanuts before serving.