Preheat the oven to 450°F (225°C). Grease a skillet or baking pan.
Combine all the dry ingredients in a large mixing bowl: oat flour, spelt flour, cornstarch, baking soda, salt, and caraway seeds.
In a separate container, whisk together the buttermilk and egg until well combined.
Create a well in the center of the dry ingredients and pour in the buttermilk mixture.
Using a spoon, gently stir the mixture until a dough forms. Be careful not to overmix.
Transfer the dough onto a floured surface and knead it gently a few times to shape it into a round circle.
Place the shaped dough into the prepared skillet or baking pan.
Using a sharp knife, score a cross on the top of the dough. This helps the bread expand while baking.
Bake in the preheated oven for 10 minutes, then reduce the temperature to 400°F (200°C).
Continue baking for another 35-40 minutes, or until the bread is deep golden brown and sounds hollow when tapped on the bottom.
Remove from the oven and allow it to cool in the pan for a few minutes.
Transfer the bread to a wire rack to cool completely before slicing.
Serve sliced and enjoy with your favorite spreads or as a side to soups and stews.
