Heat oven to 180 C and line a muffin tin with cups.
Whisk flour sugar baking powder salt and cinnamon in a bowl.
In another bowl mix applesauce eggs oil milk and vanilla until smooth.
Pour wet mix into dry mix and stir with a spatula until the flour just disappears.
Fold in chocolate chips if using.
Divide the batter among 12 cups about three quarters full.
Bake on the middle rack for 18 to 20 minutes until the tops spring back to a light press.
Cool five minutes in the tin then move muffins to a rack to cool.