In a blender, combine the frozen banana, natural peanut butter, flaxseeds or chia seeds, spinach, almond milk, and honey or maple syrup.

If you're using protein powder, add it to the blender as well.

Blend until smooth and creamy.

If the smoothie is too thick, you can add more almond milk until you reach your desired consistency.

Taste the smoothie and adjust sweetness if needed by adding more honey or maple syrup.

Pour into a glass and enjoy immediately!