Heat the oven to 400°F (200°C) and line a baking sheet with parchment.

In a big bowl whisk together the flour, baking powder, salt, and the optional onion/garlic powders until evenly mixed.

Add the chilled butter cubes. Work the butter into the flour with a pastry cutter or your fingertips until the mix looks like coarse crumbs with pea-sized bits of butter. Those visible butter bits create flaky layers.

Pour in the cold buttermilk and fold gently with a spatula just until the dough holds together. Resist the urge to keep mixing — don’t overwork it.

Lightly flour your counter and turn the dough out. Pat it into a rough rectangle about ½-inch thick.

Do the folding trick: flatten the dough, fold it into thirds like a letter, rotate, flatten again, and repeat this fold/rotate cycle 2–3 times. This quick lamination gives you the lift and flakiness of a layered biscuit.

Roll the dough to about ½ inch thick. Use a round cutter (or a glass) to stamp out circles. Arrange half the rounds on the prepared sheet.

Sprinkle a little cheddar and a few pieces of ham onto each base round. Top with the remaining rounds and press edges lightly to seal.

Brush the tops with the beaten egg for a shiny, golden finish.

Bake 15–18 minutes, until the biscuits puff and turn a warm golden brown. Let them rest a couple minutes before serving. Garnish with parsley or chives if you like.