• Preheat oven to 400°F. Line a large baking sheet with parchment paper or a silicone baking mat. Set aside

Make the dough

• In a large bowl, combine flour, salt, baking powder, baking soda, and brown sugar. Mix well, making sure that no large clumps of brown sugar remain.
• Work the butter cubes into the mixture. I use a pastry cutter. Fingers work well, too. When done, it should be a coarse, meal-like texture. Set aside.
• In a small bowl, whisk the egg. Add the sour cream and heavy cream and whisk to mix well.
• Add to the flour and butter mixture. Use a form to stir everything together, just until moistened. Do not over mix.
• Gently fold in the peaches using a rubber spatula.
• Pour the dough onto a floured work surface or baking mat. Knead lightly until the dough becomes workable.
• Gently roll or pat into an 8-inch circle.
• Cut the dough into 8 equal wedges. Transfer each wedge onto the baking sheet, placing them about 2-inches apart.
• Lightly brush each scone with the egg wash. Sprinkle the tops with sugar.
• Bake until light golden brown, about 18 to 20 minutes.
• Cool for 10 minutes on the baking sheet. Make the glaze while they cool.

Make the glaze

• In a small bowl, whisk together the heavy cream and vanilla.
• Add the confectioners sugar and whisk until smooth. Adjust the consistency by adding confectioners sugar or cream (to thicken or thin, accordingly)
• Drizzle over the semi-warm scones and serve.