Preheat your oven to 350°F (175°C) and prepare a muffin pan by greasing or lining it with paper liners.

In a large bowl, whisk together the vegetable oil, granulated sugar, and eggs until smooth and creamy.

Add the buttermilk, fresh orange juice, salt, and orange zest to the egg mixture, whisking until fully combined.

Mix in the baking powder and baking soda, then gently fold in the all-purpose flour and cranberries.

Evenly fill the muffin wells about two-thirds full with the batter.

Bake for 18-23 minutes, or until a toothpick comes out clean.

Allow the muffins to cool in the pan for about 10 minutes before transferring to a wire rack.

For the optional glaze, whisk together powdered sugar, orange juice, and zest until smooth.

Drizzle the glaze over the cooled muffins and let it set for 15 minutes before serving.