Preheat oven to 350F. Roll pastry out on lightly floured surface to 11x14-inch rectangle. Using 3- to 4-inch heart-shaped cookie cutter, cut out hearts. Transfer to cookie sheet. Combine sugar and nutmeg in bowl. Sprinkle over hearts. Bake until cookies are puffed and golden brown, about 15 minutes. Transfer to rack and cool. (Can be made 1 day ahead. Store airtight.)
