Preheat oven to 350 degrees. Lightly butter a 9-inch square baking dish. Sift flour, sugar, baking powder and salt into mixing bowl. Stir in buttermilk, cranberries and walnuts. Spread batter in bottom of prepared baking dish. In another bowl, mix brown sugar and cinnamon. Place the butter on top. Bring orange juice and water to a boil on top of stove or in microwave oven. Pour boiling liquid over brown sugar mixture and stir to mix. Pour hot mixture over cake batter in dish. Do not mix or stir. Bake pudding cake in 350-degree oven for 45 minutes. Allow to cool a bit before serving. The cake will be at the top and the brown sugar mixture will have become a caramel-like pudding sauce underneath. It’s best served warm. It’s good for breakfast with a dollop of plain or vanilla yogurt.