Set your oven to 425°F and give a 9-inch round cake pan a thorough coating of butter or cooking spray. The high heat creates the crisp crust that makes this bread special.
In a large mixing bowl, whisk the whole wheat flour, all-purpose flour, baking soda, and salt until evenly distributed. The baking soda needs to be completely incorporated — any lumps will create bitter spots.
Create a deep well in the center of your flour mixture and pour the buttermilk straight in. The acid in the buttermilk is what activates the baking soda, so work quickly once they meet.
Using a wooden spoon, stir from the center outward just until the flour disappears into a shaggy, slightly sticky dough. Stop the moment it holds together — overworking will make the bread tough and dense.
Dust your work surface with flour and turn out the dough. With floured hands, gently shape it into a round loaf about 7 inches across. Don't knead or press hard — just coax it into shape.
Transfer the loaf to your prepared pan and use a sharp knife to cut a deep X across the entire surface, going about halfway through the dough. This traditional cross helps the bread bake evenly and prevents cracking.
Scatter the oats over the top if you're using them, pressing lightly so they stick. They add a pleasant texture and rustic appearance to the finished loaf.
Bake until the crust turns deep golden brown and tapping the bottom produces a hollow sound — this means the interior is fully cooked. The top should feel firm and spring back lightly when pressed.
⏱ 45 min
Let the bread rest on a wire rack to prevent the bottom from getting soggy. The crumb needs this time to set properly, and slicing too early will give you gummy pieces instead of clean slices.
⏱ 10 min