01 - Preheat oven to 375°F. Line a 12-cup muffin tin with paper liners or grease thoroughly with butter or cooking spray.
02 - In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, baking soda, baking powder, and salt until evenly distributed.
03 - In a separate medium bowl, whisk together the buttermilk, melted cooled butter, and egg until smooth and fully incorporated.
04 - Pour the wet ingredients into the dry ingredients. Stir gently with a spatula or wooden spoon until just combined. The batter should remain slightly lumpy—do not overmix as this will result in dense muffins.
05 - Gently fold in the raisins and caraway seeds if using, distributing them evenly throughout the batter.
06 - Divide the batter evenly among the 12 muffin cups, filling each approximately three-quarters full.
07 - Bake at 375°F for 18 to 20 minutes, or until a toothpick inserted into the center of a muffin comes out clean and the tops are golden brown.
08 - Allow the muffins to cool in the tin for 5 minutes before transferring to a wire rack to cool completely.