Preheat your oven to 350°F (175°C). Grease and flour a 9x5 inch loaf pan, or line it with parchment paper, leaving an overhang on the sides to easily lift the bread out later.

In a large bowl, whisk together the all-purpose flour, granulated sugar, baking powder, baking soda, and salt. Set aside.

In a separate medium bowl, whisk the large eggs. Then, whisk in the melted butter, sour cream, fresh orange juice, orange zest, and vanilla extract until well combined.

Pour the wet ingredients into the dry ingredients. Mix with a rubber spatula until just combined. Be careful not to overmix; a few small lumps are okay.

In a small bowl, toss the cranberries with 1 tablespoon of flour from your measured amount (this helps prevent them from sinking to the bottom). Gently fold the floured cranberries into the batter.

Pour the batter evenly into the prepared loaf pan and smooth the top with your spatula.

Bake for 50-60 minutes, or until a wooden skewer or toothpick inserted into the center comes out clean or with a few moist crumbs attached. If the top starts to brown too quickly, you can loosely tent it with aluminum foil for the last 15-20 minutes of baking.

Let the bread cool in the pan on a wire rack for 15-20 minutes. Then, use the parchment paper overhangs to lift the bread out of the pan and place it directly on the wire rack to cool completely.

Once the bread is completely cool, prepare the glaze. In a small bowl, whisk together the sifted powdered sugar, 2 tablespoons of orange juice, and the optional orange zest. If the glaze is too thick, add more orange juice, 1/2 teaspoon at a time, until you reach a drizzling consistency.

Drizzle the glaze over the top of the cooled bread, letting it drip down the sides. Allow the glaze to set for about 20-30 minutes before slicing and serving.