Combine flour, brown sugar, baking powder, baking soda, and salt in large bowl or stand mixer.

Remove butter from fridge. Cut in small cubes. Mix butter into flour mixture. Finish combining the flour and butter with your hands. Squeeze flour and butter cubes together between your fingers until mixture resembles a coarse meal.

Add brie and grapes. Gently combine with rubber spatula. Slowly stir buttermilk into mixture with rubber spatula. When combined, turn dough out onto a floured surface. Knead a few times, adding flour until stickiness disappears.

Pat into 9-inch circle with hands. Cut in eighths with large knife. Place scones on parchment-lined baking sheet with at least 1 inch between each scone.

Beat egg and buttermilk in shallow bowl. Brush egg mixture over scones.

Bake 20-25 minutes until golden brown. Let cool completely.