Preheat and prep: Heat your oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners or lightly spray with nonstick spray.
Mix dry ingredients: In a large bowl, whisk flour, baking powder, baking soda, cinnamon, and salt until well combined.
This helps prevent clumps and ensures even rise.
Mix wet ingredients: In a separate bowl or large measuring cup, whisk Greek yogurt, applesauce, maple syrup, egg white, and vanilla until smooth.
Combine gently: Add the wet mixture to the dry ingredients. Stir with a spatula just until no dry streaks remain. The batter should be thick but scoopable. Do not overmix or the muffins may turn tough.
Portion the batter: Divide the batter evenly among the muffin cups.
For best results, fill each cup about 3/4 full. If using optional chocolate chips or zest, fold them in before portioning.
Bake: Place the tin on the middle rack and bake for 14–16 minutes, or until the tops spring back lightly and a toothpick comes out clean or with a few moist crumbs.
Cool: Let muffins rest in the pan 5 minutes, then transfer to a wire rack to cool completely. This prevents soggy bottoms and helps the crumb set.
Enjoy: Serve warm or at room temperature.
A light brush of warm water on top and a whisper of cinnamon can add a bakery-style finish without extra calories.