01 - Preheat oven to 400°F. Line a 12-cup muffin tin with paper liners or grease lightly with cooking spray.
02 - Whisk together all-purpose flour, whole wheat flour, sugar, baking soda, baking powder, and salt in a large mixing bowl until evenly blended.
03 - In a separate bowl, whisk buttermilk, egg, and melted butter until smooth and fully incorporated.
04 - Pour wet ingredients into dry ingredients. Stir gently with a spatula or wooden spoon just until combined; do not overmix as this will produce tough muffins.
05 - Fold in dried currants and caraway seeds if using, distributing evenly throughout the batter.
06 - Divide batter evenly among prepared muffin cups, filling each approximately three-quarters full.
07 - Bake for 16 to 18 minutes until tops are golden brown and a toothpick inserted into the center comes out clean.
08 - Let muffins cool in the tin for 5 minutes, then transfer to a wire rack to cool completely before serving.