In a blender, puree the dates, peanut butter, chia seeds, sea salt, milk, and vanilla extract until smooth (if using a high-speed blender, this will be quick; with a standard blender, you may need to scrape down the sides of the blender a few times). If you’d like additional sweetener, add the maple syrup, a teaspoon or two at a time, to taste. For the swirl: Using a blender or immersion blender, puree the berries, maple syrup, and sea salt until semi-smooth. If using frozen berries, it will take a little longer. Dollop the berry mixture on the peanut-butter pudding, or “swirl” it through!