01 - Preheat your oven to 400°F. Line a baking sheet with parchment paper or lightly grease it.
02 - In a large bowl, whisk together the whole wheat flour, all-purpose flour, sugar, baking soda, and salt until well blended.
03 - Stir in the raisins to coat them evenly with flour mixture.
04 - In a separate bowl, whisk together the buttermilk, egg, and melted butter until smooth.
05 - Pour the wet ingredients into the dry ingredients. Mix with a wooden spoon or spatula until just combined. Do not overmix as this will result in a dense loaf.
06 - Turn the dough out onto a lightly floured surface. Gently knead 4–5 times to bring the dough together. The dough will be sticky, which is normal.
07 - Shape the dough into a round loaf and place it on the prepared baking sheet.
08 - Using a sharp knife, cut a deep X across the top of the loaf to help it bake evenly.
09 - Bake for 35–40 minutes, or until the bread is golden brown and a skewer inserted in the center comes out clean.
10 - Cool on a wire rack for at least 30 minutes before slicing to allow the crumb to set.