Preheat your oven to 375°F (190°C) and line a muffin tin with paper liners.
In a large mixing bowl, combine flour, sugar, baking powder, and salt.
Add the cranberries and orange zest to the dry ingredients and mix well.
In a separate bowl, whisk together the egg, milk, vegetable oil, and vanilla extract.
Pour the wet ingredients into the dry ingredients and stir until just combined.
Divide the batter evenly among the prepared muffin cups.
Bake for 20-25 minutes or until a toothpick inserted into the center comes out clean.
Allow the muffins to cool in the tin for 5 minutes before transferring them to a wire rack.
Enjoy these muffins warm or at room temperature!