Preheat the oven to 350°F (175°C).
Line or grease a muffin tin.
In a bowl, whisk together yogurt, sugar, milk, melted butter, egg, and vanilla until smooth.
In another bowl, combine flour, baking powder, baking soda, and salt.
Gradually stir the dry ingredients into the wet. Don’t overmix.
Fill the muffin cups 2/3 full using a spoon or an ice cream scoop.
Bake for 18–22 minutes, until the muffins look golden and a toothpick comes out clean.
Let them cool in the pan briefly, then transfer to a rack.
Enjoy fresh or store airtight.