Preheat your oven to 350°F and spray a loaf pan with cooking spray. While the oven preheats, make the streusel topping by combining the 1/4 cup flour, 2 tbsp sugar, and ground cinnamon in a small bowl. Cut the softened butter into small pieces and work it into the flour mixture with your fingertips until the texture resembles coarse breadcrumbs. Transfer the streusel to the refrigerator to chill while you prepare the batter—this keeps it from spreading too much during baking. I find that chilling the streusel for at least 10 minutes makes it easier to distribute evenly over the batter.

In a medium bowl, whisk together the 2 cups all-purpose flour, 1 tsp baking soda, and 1/2 tsp salt. Make sure these ingredients are evenly distributed throughout the flour—this ensures the baking soda will activate properly and create an even crumb. Set this dry mixture aside while you prepare the wet ingredients.

In a large bowl, whisk together the room temperature egg, 1/2 cup brown sugar, and 1/2 cup sugar until the mixture is well combined and slightly lighter in color, about 1-2 minutes. This brief whisking helps incorporate air and ensures even sweetness distribution. Add the vegetable oil, 1 tsp vanilla extract, and 2 tsp fresh orange zest, whisking until smooth. Pour in the 1 cup buttermilk and whisk just until combined—don't overmix at this stage.

Pour the wet ingredient mixture from Step 3 into the dry ingredient bowl from Step 2. Using a spatula or wooden spoon, gently fold the ingredients together just until the flour is incorporated—the batter should look slightly lumpy and rough. Overmixing develops gluten and creates a dense, tough crumb, so resist the urge to make it perfectly smooth. Fold in the 1 cup coarsely chopped cranberries and 1/2 cup chopped pecans (if using), distributing them evenly throughout. For extra cranberry flavor, I like to lightly toss the chopped berries in a tiny pinch of the orange zest before folding them in.

Pour the batter into your prepared loaf pan, smoothing the top gently with a spatula. Remove the chilled streusel from the refrigerator and sprinkle it evenly over the batter, then press down very gently with your fingers—you want it to adhere slightly without compacting the batter beneath. Place the pan in the preheated 350°F oven and bake for 45 minutes to 1 hour, until a toothpick inserted into the center comes out clean or with just a few moist crumbs clinging to it. About halfway through baking (around 25-30 minutes), loosely cover the top with foil to prevent the streusel and top of the loaf from browning too quickly.

Let the bread cool in the pan for about 15-20 minutes, then turn it out onto a wire rack to cool completely. While the bread cools, prepare a simple glaze by whisking together the 1 cup sifted confectioners' sugar and 1 tbsp fresh orange juice until smooth and pourable. Once the bread has cooled completely, drizzle the orange glaze over the top in a decorative pattern. Allow the glaze to set for a few minutes before slicing—I find the bread slices much more cleanly when cooled and the glaze is set.