Preheat the oven to 350℉/176℃ and line a muffin pan with parchment liners.
Add the cooked lentils, mashed banana, applesauce, and vanilla to your blender and process until completely smooth. Then pour the mixture into a medium mixing bowl.
To the same bowl, add the flour, baking powder, and cinnamon, and mix until just combined. Then fold in the blueberries.
Scoop the mixture between 12 muffin tins and bake for 20-22 minutes, or until a toothpick inserted in the center of a muffin comes out mostly clean.
Remove the pan from the oven and let your lentil muffins rest at room temperature for 10 minutes before transferring them to a wire rack.
Notes
Use overly ripe bananas with lots of brown spots on the peel for extra sweetness. You may also use frozen bananas, just let them come to room temperature before mashing them.
Use FRESH + ACTIVE baking powder. Baking powder that has been open in the pantry for 6+ months may start to lose its effectiveness.
Don’t overmix. The texture of the muffins comes out best when folded together until just combined.
Gently tap the muffin tray on a hard surface to close up any gaps in the batter before baking.
Let your muffins rest for 10 minutes after baking. This short cool-down time will allow your muffins to completely set, and prevent them from breaking when removing them from the pan.