Preheat your oven to 375 degrees F. Grease a 12-cup standard muffin pan with nonstick spray.
In a medium bowl, stir together the whole wheat flour, baking powder, baking soda, and salt.
In another bowl, combine the yogurt, honey, eggs, butter, and vanilla extract. Whisk until well blended.
Gently stir the yogurt mixture into the flour mixture until just combined.
Fold in the diced peaches.
Divide the batter among the prepared muffin tin, using about ¼ cup for each cup.
Bake for 16 to 18 minutes, or until lightly golden brown and a cake tester comes out clean.
Remove from the oven and let cool in the tin for a few minutes before transferring to a wire rack to cool completely.
