Preheat oven to 350°F (175°C). Butter a 9 x 5-inch loaf pan (or spray with nonstick cooking spray), then set aside.
Mix butter and sugar until light and fluffy, using a stand mixer (or hand mixer).
Add eggs, vanilla, and orange zest; mix until fully incorporated.
Stir in bananas by hand. Set aside.
In a separate bowl, whisk together flour, salt, cinnamon, cardamom, baking soda, and baking powder.
Using a spatula, gently fold flour mixture into butter mixture, stopping when it's about halfway mixed in. (There should still be flour visible when you are done.)
Add the halved cranberries and chopped walnuts. Using spatula to fold them into the batter, stopping when everything is just combined (do not over-mix).
Transfer batter to loaf pan, then bake for about 45 to 50 minutes, or until a toothpick inserted in the center comes out mostly clean.
Let bread cool in pan for 15 minutes, then transfer to a wire rack to cool completely before adding glaze.
Prepare Glaze + Add Topping:
Add powdered sugar and vanilla to a medium bowl, then stir in just enough milk (starting with 1 tablespoon) so the glaze thin enough to drizzle.
Use a spoon to drizzle the glaze over the cooled banana bread. (You may have a little left over.)
Immediately sprinkle the finely chopped walnuts over the glazed bread.
Serve bread immediately, or store in an airtight container until ready to eat.
Notes
Bananas - For the best results, wait until your bananas have plenty of brown spots before making the bread. Perfectly ripe bananas won't work well.Measuring the Flour - Lightly spoon the flour into a dry measuring cup, then use a knife (or something else with a straight edge) to level off the top. Do not scoop the measuring cup into the flour. You'll end up packing the flour, and the bread will turn out dry.Making the Glaze - You can easily adjust the glaze's consistency. If it's too thick, add extra milk. If it's too thin, add more powdered sugar. The glaze will harden, so I'd recommend making it just before you add it to the bread. If it does thicken on top, stir well, and it should smooth out again.Adding the Glaze - Place a piece of foil or parchment paper under the wire rack (or set it on a baking sheet) before adding the glaze. It will make cleanup much easer!More Tips - Check out the info before this recipe card for helpful tips, variations, related recipes, and more!