Combine 1 (1/4 oz.) envelope of active dry yeast, 1⁄2 cup warm water (105º to 115º), and 1 tsp. granulated sugar in bowl of a heavy-duty stand mixer; let stand 5 minutes. Add 1 cup evaporated milk, 2 large eggs (slightly beaten), 1 tsp. of salt, and 1/2 cup granulated sugar.