01 - Preheat the oven to 375°F. Line a standard 12-cup muffin tin with paper liners or lightly grease each cup.
02 - In a large bowl, whisk together all-purpose flour, whole wheat flour, sugar, baking soda, baking powder, and salt until well blended.
03 - In a separate bowl, whisk together buttermilk, egg, and melted butter until fully combined and smooth.
04 - Pour the wet ingredients into the dry ingredients. Stir gently with a spatula or wooden spoon until just combined. Do not overmix.
05 - Gently fold in the raisins and caraway seeds, if using, until evenly distributed throughout the batter.
06 - Divide the batter evenly among the prepared muffin cups, filling each about 3/4 full.
07 - Bake for 16 to 18 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
08 - Let the muffins cool in the tin for 5 minutes, then transfer to a wire rack to cool completely or serve warm.