In a large mixing bowl, mash bananas, then whisk in sugar, egg, yogurt, oil, and vanilla extract.
Combine dry ingredients, and gently stir into banana mixture until just combined. Fold in blueberries.
Spoon mixture into muffin cups and place in a Perfect Portion Muffin Pan.
Bake for approximately 20 minutes, until golden on top and a cake tester or toothpick inserted into the centre of the muffin comes out clean. Let stand for 2 minutes, remove from Pan, and place on a cooling rack.