01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - Whisk together all-purpose flour, whole wheat flour, sugar, baking soda, baking powder, and salt in a large bowl. Stir in currants or raisins if using.
03 - Whisk together buttermilk, egg, and melted butter in a separate bowl until fully incorporated.
04 - Pour wet ingredients into dry ingredients. Stir gently with a fork or spatula until just combined; the dough will appear shaggy. Avoid overmixing.
05 - Turn dough onto a lightly floured surface. Pat into a circle approximately 1 inch thick. Cut into 8 wedges and transfer to the prepared baking sheet, spacing slightly apart.
06 - Brush tops with additional buttermilk for a shiny finish if desired.
07 - Bake for 18 to 22 minutes until scones are golden brown and a toothpick inserted into the center comes out clean.
08 - Cool slightly before serving warm with butter and jam.