Preheat oven to 350°F (177°C). Spray a standard loaf pan with nonstick spray. Set aside.
Make the streusel: Combine the flour, sugar, and cinnamon together in a medium bowl, then cut in the cold butter with a pastry cutter, your hands, or two forks, like if you're making biscuits or scones...you want pea-size crumbs.
Make the batter: In a large bowl, toss the flour, baking soda, salt, cranberries, and pecans together until combined. Set aside. In a medium bowl, whisk the egg, brown sugar, and granulated sugar together until combined. Make sure there are no brown sugar lumps remaining. Whisk in the buttermilk, oil, vanilla, and orange zest. Slowly pour the wet ingredients into the dry ingredients and gently whisk until there are no more lumps. Do not overmix.
In a medium bowl, whisk the egg, brown sugar, and granulated sugar together until it's smooth (with no lumps of brown sugar hiding in there). Whisk in the buttermilk, oil, vanilla, and orange zest.
Slowly pour the wet ingredients into the dry ingredients and gently whisk until there are no more lumps, trying not to overmix the batter.
Pour the batter into prepared loaf pan. Top evenly with the streusel, pressing it down gently into the top of the bread so it sticks.
Bake the bread for 45 minutes to 1 hour, covering loosely with foil about halfway through to ensure even browning. Use a cake tester or toothpick to check for doneness...if it comes out clean, the bread is done.
Remove the pan from oven and cool on a wire cooling rack for 15 minutes. Remove the bread from the pan and cool completely in the pan on the rack.
Make the glaze: In a small bowl, whisk the powdered sugar and orange juice together, adding more orange juice if you want the glaze to be thinner, then whisk in orange zest. Drizzle over cooled bread, then slice and serve.
Bread stays fresh at room temperature for 3 days or in the refrigerator for up to 6-7 days. For longer storage, you can freeze the unglazed bread for up to 3 months. Allow to thaw overnight in the refrigerator and bring to room temperature before glazing and serving.