By Williams Sonoma Test Kitchen
You can use supermarket lemons—Lisbon or Eureka variety—for both the doughnut batter and the glaze, but if you prefer a less tart, more floral flavor, look for Meyer lemons at a farmers’ markets or specialty stores.
To make the doughnuts, preheat the oven to 375°F. Coat the wells of a doughnut pan with nonstick cooking spray.
In a small bowl, combine the granulated sugar and lemon zest. Using your fingertips, rub the zest into the sugar. In another bowl, whisk together the flour, baking po