- Preheat the oven to 375 degrees F. Line a sheet pan with parchment paper.
- Combine the flour, sugar, baking soda, and salt in the bowl of an electric mixer fitted with the paddle attachment.
- Add the butter and mix on low speed until the butter is mixed into the flour.
- With a fork, lightly beat the buttermilk, egg, and orange zest together in a measuring cup. With the mixer on low speed, slowly add the buttermilk mixture to the flour mixture.
- Dump the dough onto a well-floured board and knead it a few times into a round loaf.
- Place the loaf on the prepared sheet pan and lightly cut an X into the top of the bread with a serrated knife. Bake for 45 to 55 minutes, or until a cake tester comes out clean. When you tap the loaf, it will have a hollow sound.
- Cool on a baking rack. Serve warm or at room temperature.