Peel and chop up potatoes. Place in pot on the stove with about 3 cups of water. Bring to a boil and cook until fork tender. Reserve 1/2 cup of potato water and mash it until smooth with drained potatoes. Set aside to cool off slightly. **For no potato chunks, use a ricer or blender. Using a potato masher or fork will have little bits of potatoes in bread which is still delicious, all personal preference though! ** While potatoes cool, put butter, brown sugar, and milk in large microwavable bowl. Heat for about 1 1/2-2 minutes, stirring every 30 seconds, and ensure that butter is melted and milk is warm, but not hot (ideally 110-115°). Mix in yeast and set aside and allow to bloom and get foamy. Slowly incorporate flour a cup at a time. At about 3 cups, add in mashed potatoes and then mix in the rest of the flour. Once dough it sticky and firm, flip onto well floured surface and knead for 5-10 minutes until dough is smooth and elastic-y. Place dough back in large bowl and cover with 2 tablespoons of oil. Cover and let rise for an hour. Once dough has risen, preheat oven to 350°. Line two baking sheets with parchment paper. Divide dough into balls. For large hamburger buns, you'll make about 20, for small slider buns or dinner rolls, you'll get about 30-40. Cover balls and let rise for 15 minutes. Place in oven and bake for 30-35 minutes for large buns, 20-25 minutes for sliders/rolls or until golden brown on the top. Remove from oven. Can be enjoyed hot or allow to cool and make sandwiches or some yummy cheeseburgers! Enjoy!