Preheat oven to 350°F (175°C). Grease a 9x5 inch loaf pan with non-stick spray or line with parchment paper, leaving overhang on both long sides for easy removal.
Rinse fresh cranberries, pat dry, and discard any soft or discolored ones. Place in a small bowl with 1 tablespoon of flour and toss to coat evenly.
Zest the orange directly into a large bowl, avoiding the bitter white pith. Juice the orange and measure 3/4 cup, removing any seeds.
In a medium bowl, whisk together 2 cups flour, sugar, baking powder, baking soda, and salt until evenly combined.
To the bowl with orange zest, add orange juice, room-temperature eggs, oil, and vanilla. Whisk until smooth and well combined.
Pour dry ingredients into wet and fold with a rubber spatula just until no flour streaks remain. Do not overmix. A few small lumps are fine.
Add flour-coated cranberries and fold gently 4 to 5 times, just until distributed. Be careful not to crush them.
Scrape batter into prepared pan and smooth the top. Bake for 55 to 65 minutes, until a toothpick inserted in the center comes out clean or with a few moist crumbs.
Let loaf cool in the pan on a wire rack for 15 minutes. Run a knife around the edges, turn out onto the rack, and cool completely for at least 1 hour before slicing.
For the glaze, whisk powdered sugar with 2 tablespoons orange juice and 1 teaspoon zest until smooth. Add more juice if needed. Drizzle over cooled loaf and let set for 15 minutes.