- Preheat the oven to 375°F. Lightly grease a baking sheet, or line with parchment.
- In a medium mixing bowl, whisk together the flour, bran, baking powder, salt, and brown sugar. Cut the butter into small pieces and work it into the dry ingredients using your fingertips or a pastry blender, until the largest bits are the size of small peas.
- Add the sour cream and heavy cream and stir just until the mixture forms large clumps. Knead once or twice with your hands (or fold the dough over on itself with a bowl scraper) until it comes together.
- On a well-floured surface, roll the dough about 1/2” thick. Cut into 2 1/2” rounds and transfer half of them to the prepared baking sheet. Stack the scraps on top of each other, fold them over once or twice, and continue to cut until all of the dough is used. You should have 16 rounds.
- Use your thumb to make an impression in the belly (center) of half of the scones. Fill the impressions with a small dollop of jam, brush the edges with the egg wash, and use one of the plain, non-indented rounds as a lid. Press gently together at the edges, sealing in the jam. Repeat with the remaining rounds.
- Brush the tops of the assembled scones with egg wash. Sprinkle each scone with about 1/4 teaspoon of coarse (or turbinado) sugar and bake for 16 to 19 minutes. Remove from the oven and let the scones cool on the pan for 5 minutes before transferring to a cooling rack.
- Store scones, well wrapped, at room temperature for a couple of days; freeze for longer storage.