Preheat the oven to 350ºF (180ºC). Grease a standard 9 x 5 inch (23 x 13 cm) loaf tin with butter, line it with parchment paper, and set it aside.
Whisk together the flour, sugar, baking powder, salt, baking soda, and the zest from one orange.
Add the softened butter to the flour mixture and continue to whisk the mixture until the butter breaks into small coarse crumbs, about 2 to 3 minutes.
Add the juice of one orange to a measuring cup and top it with warm water to the ¾ cup (175 ml) line.
Crack in the egg and whisk everything together to combine.
Pour the egg mixture into the bowl of flour and fold everything together with a wooden spoon or rubber spatula until no dry bits of flour remain. Fold in the cranberries until well combined.
Spoon the cranberry batter into the prepared loaf tin and smooth out the top with a butter knife or offset spatula.
Place the loaf in the oven and bake it for 45 minutes.
Remove the loaf from the oven, tent it loosely with aluminum foil, and return it to the oven for 15 minutes more.
Cool the loaf in the tin on a wire rack for 30 minutes, then lift it out, remove the parchment paper, and let it cool completely.
To make the orange glaze mix together the powdered sugar and zest from the second orange.
Add orange juice by the ½ teaspoon to your desired thickness, then spoon the glaze over the cooled loaf.