Preheat oven to 375ºF. Grease or line a 12-cup muffin tin with muffin papers; set aside.
In a large bowl, whisk together flour, granulated sugar, baking soda, baking powder, and salt.
In a separate bowl, stir together yogurt, melted butter, brown sugar, milk, egg, and vanilla. Add to dry ingredients and stir until nearly incorporated, with some floury patches remaining. Fold in chopped apricot.
Spoon batter into prepared muffin tin. Top muffins with an additional apricot slice, if desired. Bake for 18-22 minutes, until golden brown and tops spring back when lightly pressed. Let cool a few minutes in the pan, then transfer to wire racks to finish cooling.