01 - Preheat the oven to 400°F. Line a baking sheet with parchment paper or lightly grease it.
02 - In a large bowl, whisk together the flour, sugar, baking soda, and salt until well blended.
03 - In a separate medium bowl, whisk the buttermilk, egg, and melted butter until fully combined.
04 - Pour the wet mixture into the dry ingredients. Add raisins and orange zest. Stir with a wooden spoon until a shaggy, sticky dough forms.
05 - Turn dough onto a lightly floured surface. Knead gently just until it holds together, avoiding overworking. Shape into a 7-inch round loaf and place on the prepared baking sheet.
06 - Cut a deep X across the top of the loaf with a sharp knife, about 1/2 inch deep. Bake for 35-40 minutes until golden brown and a skewer inserted in the center comes out clean.
07 - Transfer to a wire rack and cool for at least 30 minutes before slicing to allow the crumb to set properly.