Preheat oven to 375 F. Prepare muffin pan with grease and paper.
If using sun dried tomatoes, rehydrate in a bowl of warm water for 10 minutes before chopping.
In a large mixing bowl, whisk together flour, baking powder, salt, cayenne, and pepper. Stir in rosemary, feta, olives, and tomatoes then stir to coat.
In a separate bowl, combine buttermilk and butter. Whisk in yogurt and eggs until almost smooth.
Using a rubber spatula, fold the yogurt mix into the flour mix until only just combined.
Divide batter evenly between cups. Muffins will rise slightly while baking, so leave some room if you don't want spillover.
Bake until muffins pass the toothpick test, about 25 minutes, rotating the pan halfway through. Let cool about 5 minutes in pan before removing, and enjoy!
Notes
If using standard muffin tins, increase the baking temperature to 400 F, and bake for 20-25 minutes.