Combine 4 to 6 tablespoons milk, 2 tablespoons peanut butter, and 1 pint vanilla ice cream in a blender or a food processor fitted with a blade attachment. Pulse 8 to 10 times or until mostly smooth. Add 3 teaspoons roasted, salted peanuts and pulse 4 to 5 times more to combine. Drizzle about 1 tablespoon hot fudge sauce down the sides of a chilled pint glass. Pour the shake into the glass, top with some more finely chopped peanuts, and serve.