1. Heat the oven to 400 degrees . Line a baking sheet with parchment paper.
2. In a medium bowl, whisk together the first four ingredients. Cut the butter into cubes, then add it to the bowl. Use a pastry blender or your fingers to combine the mixture until it's crumbly.
3. In a small bowl, whisk together the egg and milk. Add it to the flour mixture. Use a fork to stir the ingredients until they pull together into a dough.
4. Dust your hands and a work surface with flour. Knead the dough until smooth. Divide it into two equal portions. Roll each into a ball and flatten it into a 7-inch disk. Transfer one disk to the prepared baking sheet. Spread it with the jam, leaving a 1/2-inch border. Lay the other disk on top and pinch the edges to seal them.
5. Cut the dough into 8 equal wedges. Space them 1/2 inch apart and brush the top of each with egg wash.
6. Bake the scones until lightly browned, about 15 minutes.