Preheat the oven to 350˚F. Butter an 8 1/2 x 4 1/2-inch loaf pan, dust with flour, and tap out any excess.
In a medium bowl, whisk together flour, baking powder, and salt, then set aside.
In a measuring cup, mix milk, orange zest (reserving 1 teaspoon for glaze), and orange juice, then set aside.
In a large bowl, beat butter and sugar on medium-high speed for 2-3 minutes until combined.
Add eggs one at a time, mixing well after each addition.
Gradually add the flour mixture in two parts, alternating with the milk mixture, and mix on medium-low speed until just incorporated.
Scrape down the sides as needed.
Toss cranberries with 1/2 tablespoon of flour, then gently fold them into the batter.
Spread the batter evenly in the prepared pan.
Bake for 45-50 minutes, or until the top is golden and a toothpick inserted in the center comes out clean.
Let the loaf cool in the pan for 10-15 minutes, then run a knife around the edges and transfer it to a wire rack to cool completely.
In a small bowl, mix powdered sugar, orange juice, and reserved zest until smooth.
Adjust consistency by adding more juice if too thick or more sugar if too thin.
Drizzle the glaze over the cooled loaf, let it set, then slice and serve.