Preheat oven to 400°F. Spray 6 muffin cups with flour-added cooking spray or line with paper liners
In a mixing bowl, combine the flour, flaxseed, baking powder, baking soda and salt.In a second bowl or glass measuring cup, whisk the maple syrup, yogurt, egg, oil and vanilla until smooth.
Add the yogurt mixture to the flour mixture and stir until incorporated, then stir in the chocolate chips.
Pour into cups and bake on center rack for 18 to 22 minutes.