In a blender, puree the bananas, strawberries, spinach, greek yogurt, honey and peanut butter until smooth. You don't want any chunks. Once blended pour the mixture into a bowl.
Stir in one egg.
Gradually add the flour, baking soda and salt. Mix until just combined.
Place muffin liners in a muffin pan. Scoop the batter into the pan, filling about three quarters full.
Bake for 16-19 minutes or until a toothpick comes out clean.
Allow muffins to cool before removing them from the pan. Store in an airtight container.