Step 1

Preheat the oven to 330°F. (yep, you read that correctly!). Spray two 5x8-inch loaf pans nonstick spray (or, if making mini loaves, spray six 2-cup capacity pans).

Step 2

With an electric or standing mixer on medium speed, combine the butter and sugar together in a large bowl until pale and fluffy, about 3 minutes. Add the eggs, one at a time, mixing well after each. Add the orange juice, sour cream, orange zest, and vanilla; mix until blended.

Step 3

In a separate bowl, whisk together the flour, baking powder, and salt. Add the flour mixture and cranberries to the wet ingredients and mix just until the dry ingredients are absorbed; do not overmix.

Step 4

Divide the batter evenly between the prepared loaf pans. Bake until a toothpick inserted into center of the breads comes out clean, 70 to 75 minutes for large loaves and 55 to 60 minutes for mini loaves.

Step 5

Meanwhile, in a small bowl, whisk together the powdered sugar and 6 tablespoons Grand Marnier (or orange juice). The glaze should have the consistency of thick maple syrup or corn syrup. If it is too thick, thin with an additional tablespoon or two of the liqueur.

Step 6

Let the loaves cool in the pans for 10 minutes, then remove and transfer to a cooling rack set over a large baking sheet. With a thin skewer or long toothpick, poke deep holes in the tops of the loaves. Drizzle with Grand Marnier glaze so that it coats the top, runs down the sides, and seeps through the holes.

Step 7

Let the loaves cool completely, then slice and serve, or wrap and freeze.