In a large bowl, mix together 2 cups of the flour, ½ cup of the sugar, baking powder, baking soda, and salt. In a medium heatproof bowl, melt 2 tablespoons of the butter in microwave, then whisk in buttermilk, then egg. Pour wet mixture over dry mixture. Gently stir and fold until just incorporated. Toss cranberries in a tablespoon of flour, then fold into the batter.
Heat oven to 375 F. Evenly distribute batter into the cups of muffin pans (makes 15 muffins), either greased or paper-lined. Bake 20 to 25 minutes, until a toothpick comes out clean. Cool a few minutes before loosening sides with a knife and turning muffins out onto a wire rack. For sparkling tops, lightly brush the top of each cooled muffin with remaining tablespoon melted butter and dip to coat in the remaining ¼ cup of sugar.
Per serving: 140 calories, 3 grams fat (2 grams saturated fat), 25 grams total carbohydrates, 20 milligrams cholesterol, 253 milligrams sodium, 1 gram fiber, 3 grams protein.
