For a small batch (about 2 1/2 cups), you can actually quarter the recipe. Weigh out ¼ of all ingredients and for the eggs, use 1 large egg, but very carefully discard about half the white. My icing had the perfect texture, but I wanted more sweetness and ended up adding about 1/4 cup of confectioners' sugar at the end. Also, for testing purposes I managed to get away with using 2% milk. For a full batch, I'd stick with whole.