Add the ripe banana, frozen berries, peanut butter, and milk into your high-powered blender.
Blend on high for about 30 seconds, until the mixture is thick, smooth, and vibrant in color. You should hear it swirling and see a creamy consistency forming.
Stop the blender and give the mixture a quick stir to ensure everything is evenly blended, especially if some berries are still frozen chunks.
Scoop the thick smoothie into a wide bowl, making sure to leave some space for swirling.
Add a spoonful of jam or jelly onto the surface of the smoothie, then gently swirl it in with the back of a spoon to create a marbled effect.
Top the bowl with your favorite toppings, such as sliced fruit, granola, or a drizzle of honey, for added crunch and flavor.
Enjoy immediately with a spoon, savoring the cool, textured, and flavorful combination of nutty, fruity, and sweet elements.