Powdered Lemon Zest

In a small bowl, combine the lemon zest and sugar and rub the sugar into the zest. Spread the sugared zest in a thin layer on a plate. Place the plate in the bread proofer with the temperature set at 110°F/43°C (or in the oven with the light turned on). Let the zest dry to the touch, about 4 hours, scraping the plate every hour to dislodge any zest stuck to the plate. (The zest can be dried at