Place the frozen banana slices into your high-powered blender.
Add the peanut butter and fruit jam to the blender.
Pour in the milk to help with blending, starting with ¼ cup.
Secure the lid on the blender and blend on high until the mixture is thick, smooth, and creamy, about 30 seconds. You should hear a consistent hum and see the ingredients fully incorporated.
Stop the blender and use a spatula to scrape down the sides, ensuring everything is evenly blended.
Taste the smoothie and adjust sweetness or thickness by adding more jam or milk if needed, then blend briefly again.
Pour the thick, creamy smoothie into a serving bowl, smoothing the surface with the back of a spoon.
Decorate the top with your favorite toppings like granola, fresh berries, coconut flakes, or a drizzle of honey for added crunch and flavor.
Serve immediately to enjoy the vibrant colors, textures, and fresh aroma.