6tablespoons(3/4 stick) cold unsalted butter, cut into 1/2-inch cubes
6ozCheddar, coarsely grated (1 1/2 cups)
3scallions, finely chopped
1cupwell-shaken buttermilk
Preheat oven to 450°F.
Whisk together flour, baking powder, sugar, baking soda, and salt in a bowl, then blend in butter with your fingertips until mixture resembles coarse meal. Stir in Cheddar and scallions. Add buttermilk and stir until just combined.
Drop dough in 12 equal mounds about 2 inches apart onto a buttered large baking sheet. Bake in middle of oven until golden, 18 to 20 minutes.