1 stick (4 ounces) unsalted butter, VERY cold and cut into tiny pieces
1 large egg, at room temperature
3/4 cup plus 2 tablespoons whole milk (full-fat)
4 ounces Parmesan cheese, shredded
4 ounces ham, diced
1/4 cup fresh rosemary, chopped
Preheat oven to 400°(F). Line a large baking sheet with parchment paper; set aside.
In a large bowl add the flour, salt, baking powder, baking soda, and brown sugar; mix well to combine. Cut the butter into small cubes then quickly work it into the mixture (using your fingers, two forks, or a pastry cutter) until it resembles a coarse meal. Set aside. In a small bowl whisk together the egg and milk, beating well to combine. Add the liquid mixture to dry and use a fork to stir everything together until just moistened.
Add in the Parmesan cheese, ham, and rosemary and gently fold them into dough with a spatula.
Pour the shaggy dough out onto a clean, floured work surface and shape the dough into an 8-inch circle. Cut the dough into 8 wedges and carefully transfer to the prepared sheet.
Bake for 18-20 minutes, or until the tops are lightly golden brown.