Preheat the oven to 425°F. In a large bowl, whisk together the flour, sugar, baking soda, baking powder, and salt. In a smaller bowl, combine the buttermilk, egg, and melted butter.
Create a well in the center of the dry ingredients, then pour in the wet mixture. Use a wooden spoon to stir the wet ingredients until they begin to mix with the dry ingredients, forming a sticky dough.
When the dough can no longer be combined with a spoon, use your hands to mix in any remaining dry ingredients.
Flour a working surface and knead the dough for about one minute or until it forms a ball.
Grease a baking sheet or cast-iron skillet with cooking oil or butter. Gently glide a knife across the top of the bread to create an "X" shape.
Bake the bread for 45-50 minutes, checking for doneness around the 30-minute mark. The bread should produce a hollow sound when tapped. Allow it to cool for 30 minutes before slicing.
Serve warm or toasted with butter or marmalade. Heads up—this bread dries out in about 2 days, so make sure to enjoy it while it's fresh. Enjoy!