Line a muffin tin with paper liners or spray with nonstick cooking spray.
If you have an electric mixer, use it to beat the applesauce and sugar until light and fluffy. I mixed the ingredients by hand, with a whisk, since I don’t have an electric mixer.
Add egg and beat well, then yogurt, lemon juice, banana and zest.
If you have a sifter, sift together flour, baking powder, baking soda and salt and sift half of dry ingredients over batter. I don’t have a sifter, so I mixed the dry ingredients together in a separate bowl and added it to the bowl of liquid ingredients.
Mix until combined.
Sift (or add) remaining dry ingredients into batter and mix just until the flour disappears.
Gently fold in your blueberries (or whatever fruit you’re using).
Bake for 25 to 30 minutes, until the tops are golden.