Preheat your oven to 375°F (190°C). Line a muffin tin with paper liners or grease with cooking spray.
In a medium bowl, combine the chopped cranberries and the zest of one orange. Set aside.
In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, brown sugar, baking powder, baking soda, and salt until well combined.
In another bowl, beat the egg well, then add the vegetable oil, buttermilk, orange juice, and vanilla extract. Whisk until everything is blended smoothly.
Pour the wet ingredients into the dry flour mixture. Gently mix until just combined; be careful not to overmix.
Fold in the cranberry and orange zest mixture until evenly distributed throughout the batter.
Divide the batter evenly among the muffin cups, filling each about ¾ full.
Bake in the preheated oven for 18-20 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
Once baked, remove the muffins from the oven and allow them to cool in the tin for 5 minutes before transferring them to a wire rack to cool completely.
Notes
Serve the muffins warm on a decorative platter, garnished with a few fresh cranberries and slices of orange for added flair.