Savory Prosciutto Muffins

Preheat oven to 400 degrees F. Coat 12 (1/2-cup) muffin cups with cooking spray.

Melt butter in a large skillet over medium heat. Add onion and cook, stirring, until golden, about 5 minutes. Stir in prosciutto and cook, stirring, for 2 minutes. Remove from the heat.

Whisk flour, rosemary, baking powder, baking soda, salt and pepper in a large bowl until combined. Whisk buttermilk, eggs and oil in a medium bowl until blended.

Fold the onion mixture and buttermilk mixture into the dry ingredients with a rubber spatula until evenly moistened. Divide the batter among the prepared muffin cups.

Bake the muffins until lightly browned and a toothpick inserted in the center comes out clean, 18 to 20 minutes. Serve warm.