Preheat the oven to 350°F / 175°C. Butter and flour or use non-stick baking spray to grease a 10-inch Bundt pan with 10 cup capacity. Be sure to get into all the nooks and crannies of your Bundt pan to ensure an easy release.
Whisk together the all-purpose flour, granulated sugar, baking powder, and salt in a large bowl and set aside.
In a separate large bowl, add the eggs, buttermilk, sour cream, oil, orange juice, orange zest, and vanilla. Whisk until combined.
Mix in half of the the dry ingredients until they are just combined. Stir in the remaining dry ingredients. Be careful not to over-mix the batter.
Pour 1/3 of the batter into the pan, and add half the chopped cranberries that have been tossed in flour. Top with another 1/3 of the batter, then add the remaining cranberries. Top with the rest of the batter. This ensures that the cranberries will be evenly distributed once the cake is baked.
Bake for 55-65 minutes, or until a toothpick comes out clean. My Bundt pan took about 63 minutes.
Allow the cake to cool in the pan for about 30 minutes. Use a serrated knife to level the bottom of the cake to help it sit flush against your plate or cake stand.
Carefully invert the pan and flip the cake onto the plate or cake stand.