Step 1

Preheat your oven to 375°F. Grease well an 8.5-inch x 4.5-inch loaf pan, then line it with some parchment paper, hanging off the sides. You can also use a standard 9-inch by 5-inch loaf pan. Set it aside.

Step 2

In a large bowl, place the flour blend, xanthan gum, cornstarch, oat flour, baking powder, baking soda, salt and sugar, and whisk to combine well.

Step 3

Add almost all the rolled oats, reserving about 1 tablespoon to sprinkle on top of the raw batter in the loaf pan. Whisk to evenly distribute the oats in the dry ingredients.

Step 4

Create a well in the center of the dry ingredients, and add the buttermilk, butter, and eggs.

Step 5

Mix to combine fully, but do not overmix. The batter will be thick but should not be stiff.

Step 6

Scrape the batter into the prepared baking pan and, with a wet spatula, smooth the top.

Step 7

For a more uniform split down the center as the bread rises in the oven, slash down the center of the loaf with a knife or small metal offset spatula, about 1/4-inch deep.

Step 8

Sprinkle the reserved rolled oats evenly on top of the batter in the loaf pan. Bang the pan on the counter a couple times to help the loose oats adhere to the batter.

Step 9

Place the pan in the center of the preheated oven and bake for 10 minutes.

Step 10

Reduce the oven temperature to 350°F, and continue to bake for another 45 to 50 minutes, or until the top of the loaf springs back when pressed lightly and a toothpick inserted in the center comes out with, at most, a few moist crumbs attached.

Step 11

Remove from the oven and allow to cool in the loaf pan for 15 minutes before transferring to a wire rack to cool completely. Slice once cool and serve.