Preheat the oven to 375°F. Grease an 8-inch square pan with butter or nonstick cooking spray.
In a large bowl, whisk together the flour, baking powder, baking soda and salt.
Toss in the cold butter. Using a pastry cutter, two butter knives, or your fingers, cut or rub the butter into the flour mixture until the mixture is crumbly, with some pea-size clumps of butter within. Mix in the cheese.
In a separate bowl, whisk together the buttermilk and the egg. Add to the dry ingredients and stir until everything is just moistened. Do not overmix.
Transfer the sticky dough to the prepared pan. Dust your hands with flour and press the dough to the edges of the pan. Bake the bread for about 35 minutes, until golden brown, set, and a cake tester comes out clean. Let the bread cool in the pan for about 5 minutes, then turn out onto a rack to cool. Cut into squares and serve warm.
Note: If you’d like to make your own buttermilk, check out the easy method here.
Freezer-Friendly Instructions: The bread can be frozen for up to 3 months. Once it’s completely cooled, wrap it securely in plastic wrap and place in the freezer. To reheat, wrap the bread in aluminum foil and warm it in a 350°F oven until hot.
