01 - Preheat the oven to 400°F. Line a baking sheet with parchment paper.
02 - Whisk together the all-purpose flour, whole wheat flour, sugar, baking soda, baking powder, and salt in a large bowl.
03 - Add cold butter cubes to the flour mixture. Cut into the flour using a pastry cutter or fingertips until mixture resembles coarse crumbs.
04 - Stir in raisins or currants and caraway seeds if using.
05 - Whisk buttermilk and egg together in a small bowl. Pour into dry mixture and stir gently until just combined. Do not overmix; dough will be shaggy.
06 - Turn dough onto a lightly floured surface. Pat into a 1-inch thick round. Cut into 8 wedges and transfer to prepared baking sheet.
07 - Brush tops with buttermilk and sprinkle with coarse sugar if desired.
08 - Bake for 16 to 18 minutes until golden brown and a toothpick inserted in center comes out clean.
09 - Cool slightly before serving warm with butter and jam.