For the Muffins

1. In a large bowl, combine the flour, baking powder, baking soda, and salt to a medium or large bowl, and whisk together until they are thoroughly combined.
2. In a separate large bowl, add the sugar and orange zest. Use your fingers to rub the zest into the sugar. Add in the oil and butter, and use an electric mixer to mix until fluffy.
3. Next, add the eggs one at a time and mix until the last egg is just combined. Mix in the sour cream and orange juice until combined.
4. Fold about ⅓ of the dry ingredients into the wet ingredients with a wooden spoon or silicone spatula, then pour in about ¼ cup of the buttermilk and stir. Continue alternating the dry ingredients and buttermilk until everything is incorporated and all of the ingredients are just combined. Try not to overmix. The batter will be thick.
5. Fold in the cranberries, then cover the bowl loosely with plastic wrap or a tea towel. Let it rest at room temperature for 45 minutes. While the batter is resting, preheat the oven to 425°F.
6. Line two (12-cup) muffin tins with 6 liners each, one in every other cup. Use a cookie scoop to fill each liner to the top, about 4 ½ tablespoons of batter each.
7. First bake at 425°F for 5-6 minutes. Then, without opening the oven, lower the temperature to 350°F, and bake for another 12-13 minutes or until the muffins are tall and a toothpick inserted in the center of the muffins comes out clean.
8. Let the muffins rest in the pan for 10-15 minutes, then transfer to a cooling rack and let them cool to room temperature.

For the Orange Glaze

1. Stir the powdered sugar, orange juice, and salt (optional) in a small bowl until smooth. Drizzle over the cooled muffins. For a thicker glaze, stir in 1 tablespoon of powdered sugar at a time until the desired consistency is reached. For a thinner, stir in 1 tablespoon of milk at a time.