Preheat the oven to 400 degrees. Line a muffin tin with paper muffin/cupcake wrappers.
In a large bowl, whisk together the flour, baking soda and powder, salt and cinnamon.
In a medium bowl, mix the maple syrup, vanilla, lightly-beaten egg, yogurt, oil, kale and mashed banana.
Add wet ingredients to dry ingredients and stir. Gently fold in the frozen blueberries.
Fill the muffin cups about 2/3 full and bake for 12-15 minutes or until a toothpick inserted into the center of the muffin comes out clean.