Preheat your oven to 330°F and spray two loaf pans with cooking spray. While the oven heats, gather all ingredients and prepare your mise en place: finely grate the orange zest from 1-2 oranges, squeeze fresh orange juice to measure 1 cup, roughly chop the dried cranberries (this helps them distribute evenly throughout the batter), and sift the powdered sugar to remove any lumps. Bring your eggs and butter to room temperature—this ensures proper emulsification and a tender crumb. I find that taking just 5 minutes for thoughtful prep prevents mixing issues later.

In a large mixing bowl, cream together the softened butter and granulated sugar for 3 minutes on medium speed until the mixture is pale, fluffy, and nearly doubled in volume. This incorporates air and creates a lighter crumb structure. Add the room-temperature eggs one at a time, mixing well after each addition. Taking time between eggs ensures proper emulsification and prevents the batter from curdling.

Add the orange juice, sour cream, orange zest, and vanilla extract to the butter-egg mixture and blend on medium speed until well combined. The sour cream adds tang and tenderness while the orange juice and zest layer in bright citrus notes. Mix just until smooth; overmixing at this stage can develop gluten and make the bread tough.

In a separate bowl, whisk together the all-purpose flour, baking powder, and salt. Add this dry mixture to the wet ingredients from Step 3 along with the chopped cranberries. Fold gently with a spatula or mix on low speed just until the dry ingredients are absorbed—do not overmix. The cranberries are added here at the end to prevent them from sinking to the bottom. I prefer to toss them lightly in a tablespoon of flour from the measured amount before folding to help them suspend throughout the batter.

Divide the batter evenly between the two prepared loaf pans, smoothing the tops gently. Bake at 330°F for 70 to 75 minutes for large loaves, or 55 to 60 minutes for mini loaves, until a toothpick inserted into the center comes out clean or with just a few moist crumbs. The loaves should be golden brown on top. While they bake, start preparing the glaze.

While the loaves are baking, whisk together the sifted powdered sugar and 6 tablespoons of Grand Marnier (or brandy as a substitute) in a small bowl until smooth and pourable. The mixture should have the consistency of heavy cream—if it's too thick, add a few drops of water or extra Grand Marnier; if too thin, add a bit more powdered sugar. Let it sit until the loaves are ready.

Once baked, let the loaves cool in their pans for 10 minutes, then carefully turn them out onto a cooling rack. While still warm (but not piping hot), use a wooden skewer or cake tester to poke holes evenly across the top of each loaf. This allows the glaze to soak in and distribute its flavors throughout. Drizzle the Grand Marnier glaze generously over the warm loaves, letting it pool and seep into the holes. Allow the loaves to cool completely before slicing—this sets the glaze and allows the flavors to fully develop.