Start by pouring warm water into a small bowl, ensuring it's about 110°F. Sprinkle the active dry yeast over the water and let it sit for 5 minutes, allowing it to become frothy.

In a stand mixer fitted with a paddle attachment, combine the plain mashed potatoes, granulated sugar, and egg. Mix on low speed for about 1 minute until well blended.

Next, incorporate the dairy-free sour cream, melted vegan butter, and the frothy yeast mixture into the potato base. Increase the mixer speed to medium for 30 seconds.

In a separate bowl, whisk together the gluten-free flour blend, xanthan gum, and salt. Gradually mix this dry blend into the wet mixture.

Grease a 9"x13" baking dish generously. Using your hands, portion out the dough and shape it into rolls, placing them in the dish.

Cover the baking dish with a clean kitchen towel and place it in a warm area to rise for 50 to 65 minutes.

As your dough rises, preheat your oven to 375°F.

Carefully place the baking dish in the preheated oven and bake for 25 to 30 minutes.

Once baked, let the buns sit in the pan for about 5 minutes before gently removing them to a wire rack.