This recipe for homemade hamburger buns take a bit of time but is well worth the effort.
Mix together yeast, sugar and warm water, until yeast and sugar dissolve. Set aside.
Mix together buttermilk, olive oil, molasses, pumpkin puree, water and eggs until they are combined. Add in the yeast mixture, both flours and salt. Mix till a dough starts to form, take dough out of bowl and continue to knead the dough for about 15 minutes. (Add more flour or water as you need it, to keep the dough at a nice consistency) You should be able to stretch the dough without it breaking.
Place dough in a bowl that has been greased with some olive oil and cover. Let rise for about 2 hours, or until it has doubled in size.
Punch air out of dough. Line a couple of baking trays with parchment paper. Cut pieces off of dough and form balls a bit smaller then the palm of your hand. (This all depends on how big you want your buns) Rub a little water on bun and roll in oats. Place buns onto baking tray leaving a bit of space. (About 12 - 16 per tray) Flatten them out with the palm of your hand, and cover up again. Let rise for 2 hours.
Preheat oven to 375 degrees F.
Bake for 15 - 20 minutes, or until golden on top and when you tap the bun it sounds hollow. Let cool, once cool enough to touch take off of pan and let cool on a wire rack.