In a blender or food processor, add eggs, butter, lemon juice, sugar and then bananas (in that order).
Turn blender on high and blend until fully combined and silky smooth.
If using food processor, start on low and then switch to high to achieve an extremely smooth consistency.
Pour all ingredients into a medium sauce pan over medium-low heat. Stir constantly for about 5-10 minutes or until mixture thickens and coats the back of your spoon.
Remove from heat and allow to cool completely. (Can refrigerate for 2-3 hours to expedite)
Can be stored in an airtight container and refrigerated for 2 weeks. Makes about 4 cups.