Start by combining the warm water, quick rise yeast, and 2 teaspoons of sugar in a small bowl. Give it a gentle stir and let it sit for about 5-10 minutes until it becomes frothy.
In a large mixing bowl, combine the melted butter, 2/3 cup sugar, warm milk, warmed mashed potatoes, and eggs. Use a whisk to mix until smooth and well combined.
Once your yeast mixture is ready, add it to the wet ingredient mixture. Then, start adding in the flour and salt gradually. Mix until a dough forms.
Turn the dough onto a floured surface and begin kneading. If the dough is too sticky, gradually add more flour, one tablespoon at a time, until it becomes smooth and elastic, about 5-7 minutes.
Place the dough in a greased bowl and cover it with a kitchen towel. Allow it to rise in a warm place until it doubles in size, approximately 1 hour.
Once the dough has risen, punch it down to release the air. Divide the dough into equal portions (about 12-15 rolls), and shape them into balls. Place the rolls on a greased baking sheet, leaving some space between each one.
Cover the shaped rolls with a kitchen towel again and let them rise for another 30-45 minutes, or until they are puffy.
Preheat your oven to 375°F (190°C). Bake the rolls for 15-20 minutes, or until golden brown.
Once out of the oven, let the rolls cool for a few minutes before serving. Slather them with butter, and watch them disappear!