4 and 1/4 cups (531g) all-purpose flour (spoon & leveled), plus more for your hands and counter
3 Tablespoons (38g) granulated sugar
1 teaspoonbaking soda
5 Tablespoons (70g) unsalted butter, cold and cubed*
optional: 1 cup (150g) raisins
Preheat oven & pan options: Preheat oven to 400°F (204°C). There are options for the baking pan. Use a regular baking sheet and line with parchment paper or a silicone baking mat (bread spreads a bit more on a baking sheet), or use a seasoned 10-12 inch cast iron skillet (no need to preheat the cast iron unless you want to), or grease a 9-10 inch cake pan or pie dish. You can also use a 5 quart (or higher) dutch oven. Grease or line with parchment paper. If using a dutch oven, bake the bread with the lid off.
Whisk the buttermilk and egg together. Set aside. Whisk the flour, granulated sugar, baking soda, and salt together in a large bowl. Cut in the butter using a pastry cutter, a fork, or your fingers. Mixture is very heavy on the flour, but do your best to cut in the butter until the butter is pea-sized crumbs. Stir in the raisins. Pour in the buttermilk/egg mixture. Gently fold the dough together until dough it is too stiff to stir. Pour crumbly dough onto a lightly floured work surface. With floured hands, work the dough into a ball as best you can, then knead for about 30 seconds or until all the flour is moistened. If the dough is too sticky, add a little more flour.
Transfer the dough to the prepared skillet/pan. Using a very sharp knife, score a 1/2 inch deep X into the top. Bake until the bread is golden brown and center appears cooked through, about 45-55 minutes. Loosely tent the bread with aluminum foil if you notice heavy browning on top. For an accurate test, bread is done when an instant read thermometer reads 190°F (88°C).
Remove from the oven and allow bread to cool for 10 minutes, then transfer to a wire rack. Serve warm, at room temperature, or toasted with desired toppings/spreads.
Cover and store leftover bread at room temperature for up to 2 days or in the refrigerator for up to 1 week. We usually wrap it tightly in aluminum foil for storing.