If your goal is an icing with a graceful drizzling consistency, we strongly recommend that you weigh your confectioners’ sugar.
Our Cider-Glazed Apple Bundt Cake is finished with an icing that drizzles smoothly in thin, delicate lines and turns matte but not brittle when it dries. But when some of our recipe testers made it, they found the icing thick and gloppy and reported that it fell off in chunks when the cake was sliced. What gives?
The recipe calls for 3/4 cup (3 ounces) of confectioners’ sugar, but if you measure by volume rather than weight, you could end up with an icing that’s too thick. Because powdered sugar is so fine and fluffy, the amount you can fit into a 3/4-cup measuring cup can vary considerably depending on how compactly you fill the cup.
When we tested various volume measuring methods—sifting the sugar before spooning it into the measuring cups, a more conventional dip-and-sweep approach, and digging into the sugar container and pressing the cup against the side to level the top—we found that the weight varied by as much as 35 percent. That variation has a significant impact on the icing’s consistency.
So if your goal is an icing with a graceful drizzling consistency, we strongly recommend that you weigh your confectioners’ sugar.