Place frozen berries, peanut butter, Greek yogurt, milk, maple syrup, and chia seeds into your high-speed blender.
Blend on high for about 30-45 seconds, stopping to scrape down the sides as needed, until the mixture is smooth, thick, and vibrant in color.
Taste the mixture and add more maple syrup if you'd like a sweeter flavor, then give it another quick blend.
Pour the thick, creamy smoothie base into bowls, using a spatula to spread it evenly and create a smooth surface.
Top the bowls with sliced strawberries, a drizzle of peanut butter, and any additional toppings you enjoy for extra flavor and texture.
Serve immediately with a spoon, enjoying the cold, colorful, and satisfying smoothie bowl.