1. In a small bowl, dissolve the yeast with 1 teaspoon of sugar in warm water. Let it sit for 5 minutes until frothy.

2. In a large bowl, whisk together the evaporated milk, melted butter, egg, remaining sugar, and salt.

3. Stir in the yeast mixture. Gradually add the flour, mixing until a soft dough forms.

4. Knead the dough on a lightly floured surface for 5-7 minutes until smooth. Place the dough in a greased bowl, cover, and let rise in a warm place for about 1 hour or until doubled in size.

5. Roll out the dough on a floured surface to about 1/2-inch thickness. Use a doughnut cutter (or two round cutters of different sizes) to cut out doughnuts. Re-roll any scraps and cut additional doughnuts.

6. Place the doughnuts on a parchment-lined tray, cover lightly, and let them rise for another 30 minutes.

7. Heat oil in a deep fryer or large, deep skillet to 375°F (190°C). Fry the doughnuts in batches for 1-2 minutes per side until golden brown. Remove with a slotted spoon and drain on paper towels.

8. For the glaze, whisk together powdered sugar, hot water, and vanilla extract until smooth.

9. While still warm, dip each doughnut into the glaze, allowing excess to drip off. Place on a rack to set.