Heat oven to 375ºF. Coat an 8-inch-by-4-inch loaf pan with cooking spray.
Grate zest from the orange into a large bowl. Cut the orange in half and squeeze in all of the juice. Whisk in flax seed "eggs", vegan buttermilk, oil, sugar, brown sugar, and salt until blended.
Stir together cornmeal, flour, baking powder and cranberries, and add them to the wet ingredients, stirring just until batter is thoroughly mixed.
Spoon into prepared pan and bake until a toothpick inserted in the center comes out clean, 35 to 40 minutes.
Cool on a rack.
Eat with cranberry chutney. (Optional)