Preheat the oven to 350°F, and line 2 standard muffin pans cups with paper liners

In a small bowl, combine ground flax and water and set aside.

In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. In a large bowl, whisk together the applesauce, flax+water mixture, and vanilla. Stir in the honey and yogurt, thoroughly mixing until no large lumps remain. Alternate between adding the flour mixture and the milk, stirring just until incorporated, beginning and ending with the flour. Gently fold in the peaches.

Divide the batter between the prepared muffin cups, and bake at 350°F for 29-33 minutes, or until a toothpick inserted into the center comes out clean. Cool in the pan for 5 minutes before carefully turning out onto a wire rack to cool completely.