In the bowl of a stand mixer, add the gf bread flour blend, granulated sugar, baking powder, salt, yeast, and psyllium husks. Whisk together. Add mashed potatoes, egg, egg yolks, butter, and milk and mix on low using the dough hook until combined. Increase the speed to medium or medium high and knead for 5 minutes.

Cover dough and allow to proof for 1-2 hours, or until doubled in size. Refrigerate at least 6 hours, but preferably overnight.

On baking day, remove the dough from the fridge and knead on a well-floured surface until smooth. Divide into 3 oz (85 g) pieces and shape into rolls by folding sides up and into the middle and pinching them together, flipping over and rolling using a cupped hand on a non-floured surface until smooth.

Place rolls an inch or two apart on a parchment-lined baking sheet (closer together if you want them to be more pull-apart style). Cover loosely with plastic wrap. Place in a warm, draft-free area to rise for 25-30 minutes, or until nearly doubled in size.

Meanwhile, preheat oven to 375° F. For floured potato buns, sprinkle risen buns with a little bit of potato starch, or you can leave buns unadorned for baking.

Bake rolls for 15 minutes, or until golden brown. They should feel very light when picked up. At this point, you can brush the buns with melted butter as an alternative to dusting with potato starch.

Let buns cool to warm or room temperature before serving.