In a large mixing bowl, combine 1 cup warm milk, 1 cup plain mashed potatoes, 2 tablespoons instant dry yeast, 1/4 cup honey, 2 teaspoons salt, 6 tablespoons salted butter (softened), 2 large eggsand most of the flour (reserve 1/2 cup to add in slowly as needed). Stir with a wooden spoon until the dough starts to come together and becomes difficult to stir.
Turn the dough out onto a clean, lightly floured surface. Knead by hand, gradually adding the remaining flour. Knead for about 8–10 minutes, folding, pressing, and turning the dough until it forms a soft, smooth, and slightly tacky ball that doesn’t stick to your hands. Adjust the amount of flour as needed to achieve the right consistency.
Transfer the dough to a large lightly greased bowl. Cover the bowl with a clean towel or plastic wrap and let the dough rise in a warm place until it doubles in size, about 90 minutes.
Lightly grease a 13x18-inch baking sheet or two 9x13-inch pans. Divide dough equally to form 24 rolls. Place the rolls on the prepared baking sheet in six rows of four. Cover again and set let rise until double in size, about 1 hour.
Preheat the oven to 375°F (190°C). Bake the rolls for 12 to 14 minutes or until lightly browned.
While the rolls are baking, melt 1 tablespoon salted butter and 1 tablespoon honey together in a small saucepan on the stove or in a small bowl in the microwave.
Remove the rolls from the oven and immediately brush the tops with the honey butter mixture. Allow the rolls to rest in the pan for 15 minutes before transferring them to a wire cooling rack. Serve warm or cool completely. Store cooled rolls in an airtight plastic bag for up to 3–4 days.
Notes
Mashed potatoes: Use leftover mashed potatoes or plain instant mashed potatoes.
Using a stand mixer: Follow the same ingredient measurements. Use the dough hook attachment on a stand mixer. Begin by combining all ingredients (except the flour) in the bowl of the mixer. Gradually add 5 1/2 cups of flour while mixing on low speed. Increase to medium speed and continue mixing until the dough pulls away from the sides of the bowl, adding the remaining 1/2 cup of flour as needed to form a soft, slightly tacky dough. Knead with the mixer for 5–7 minutes, then proceed with the rising instructions.
If using active dry yeast, simply add 10 to 15 minutes on to the initial rising time.