Preheat oven to 375 degrees F. Line 6-cup jumbo muffin pan with paper liners.
Add granulated sugar and fresh orange zest to small bowl. Stir to combine. Set aside.
Add all-purpose flour, baking powder, and fine sea salt to large mixing bowl. Whisk to combine. Add the orange sugar to the flour mixture. Whisk to combine. Set aside.
Add eggs, melted butter, vegetable oil, sour cream, whole milk, fresh orange juice, and vanilla bean paste to large mixing bowl. Whisk until smooth. Set aside.
Add the egg mixture to the flour mixture. Fold in using a large spatula. Avoid over mixing.
Add the cranberries, toasted walnuts, and chocolate to the muffin batter. Fold in using a large spatula.
Divide the muffin batter between the prepared muffin cups using an ice cream scoop.
Bake for 22 minutes or until the edges of the muffin are golden brown, the center is firm to the touch, and a toothpick inserted in the center comes out clean.
Remove the muffin pan from the oven and place on wire rack to cool for 15 minutes. Remove muffins from tin to cool completely.
Store leftover muffins in an airtight container at room temperature.