Step 1

In a small mixing bowl, stir the buttermilk and 2 cups of the oatmeal together. Set aside for one hour.

Step 2

Preheat oven to 400 degrees.

Step 3

Whisk together all purpose flour, cake flour, whole wheat flour, remaining 1/2 cup oatmeal, brown sugar, baking soda, cream of tartar, and salt.

Step 4

Use your fingers to work the 2 tablespoons of softened butter into the flour mixture, until it resembles coarse crumbs.

Step 5

Add the oatmeal/buttermilk mixture and toasted walnuts to the flour mixture, and stir with a fork until combined. You may need use your hands to work it all together.

Step 6

Knead the dough on a lightly floured surface or pastry mat just until the mixture comes together but is still slightly bumpy. Kneading it until it's smooth will overwork the dough and make your bread tough.

Step 7

Form the dough into a 6-inch disc that is about 2 inches high. Using a serrated knife, cut an X in the top of the disc. If desired, brush with a bit of buttermilk and sprinkle additional oats on top.

Step 8

Bake in a cast iron pan or on a parchment-covered baking sheet for 45-55 minutes or until a toothpick inserted in the center comes out clean. If the bread starts to brown too much, a piece of foil tented over the top will prevent further browning.

Step 9

After removing the bread from the oven, brush the top with the melted butter. Allow the bread to cool before slicing.