Preheat your oven to 375°F (190°C) and prepare a 12-cup muffin tin by greasing it or lining with paper liners.

In a large bowl, whisk together the flour, baking powder, baking soda, salt, and optional sugar.

Cut in the cold butter until the mixture resembles coarse crumbs with some pea-sized butter pieces.

Stir in the raisins or currants and optional caraway seeds until evenly incorporated.

In another bowl, whisk together the egg and buttermilk until combined.

Gently fold the wet mixture into the dry until just combined. A few lumps are fine.

Fill the muffin cups about three-quarters full with the batter.

Brush the tops with remaining buttermilk or melted butter before baking.

Bake for 18-22 minutes or until golden brown, and a toothpick comes out clean.

Cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.