Preheat oven to 350°F (175°C) and line a mini muffin tin with liners or grease it.
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt.
In a separate large bowl, mix melted butter, sugar, Greek yogurt, egg, and vanilla until smooth.
Gradually mix the dry ingredients into the wet ingredients until just combined (do not overmix).
Stir in the mini chocolate chips.
Spoon the batter into the mini muffin tin, filling each about ¾ full.
Bake for 10-12 minutes or until a toothpick inserted in the center comes out clean.
Let muffins cool in the pan for 5 minutes before transferring to a wire rack. Enjoy when cooled.