Gluten-free hamburger buns

280 grams Aherns’ all-purpose gluten-free flour
140 grams almond flour
140 grams potato flour
100 grams soy milk (if you use cow’s milk, and your sponge is runny, use less next time)
165 to 260 grams water
1 tablespoon yeast
1 teaspoon guar gum
2 tablespoons unsalted butter, melted
2 large eggs
1 1/2 teaspoons kosher salt
1 egg, well-beaten (optional)
1/4 cup sesame seeds (optional)

Combining the flours. Put the all-purpose flour, the almond flour, and the potato flour into a food processor. Mix them for a few moments until they have become one, coherent flour. Using the food processor aerates the flours in a way that seems to really help the bread. If you don’t have one, then use a stand mixer or a large bowl and whisk, then sift the flours into another bowl. This only takes a few moments, and it will really help the final buns.

Making the sponge. Measure out 210 grams of the combined flours into a large bowl. Warm the milk in a small saucepan until it is barely warm. After you have put on the milk, let your tap water run warm until it is 115 degrees. (This is the temperature when the water runs over your wrist warm, the same warmth as your flesh.) By the time you have added the water to the flour, the milk should be warm enough. If it’s hot at all, wait a few moments for it to cool down before you add it to the flours. Add the milk to the flours, then 165 grams of the water, and stir them all to combine. Stir the sponge well until it has the consistency of a thick porridge. If the sponge is too thick, add more warm water until you have the right consistency. (Each kitchen, depending on the heat and humidity, and elevation of where you are, will be slightly different.) Sprinkle the yeast over the mixture and let it sit for 3 minutes. Stir. Cover the bowl with plastic wrap and allow it to sit in a warmish place until it has doubled or tripled in volume, about 1 to 2 hours.

(Here a note. If you let the sponge go more than two hours, — say, overnight, the way I did once — you’ll have even more flavor. However, the sponge turns more liquidy the longer it goes. Adjust your flours accordingly.)

Finishing the dough. Put the remaining flour and the sponge, along with the guar gum, melted butter and eggs, into the stand mixer. (If you don’t have one, you can do this by hand, with a lot of bicep work!) Mix until the dough is coherent, about 2 minutes. Cover the bowl of the stand mixer with plastic wrap or damp towel and let it sit for 20 minutes.

Add the salt to the dough, then knead the dough in the stand mixer until it comes together into a ball, about 7 minutes. (The salt might make the dough stick to the sides of the mixer, but it will come back into a ball again. If it doesn’t, then scrape the sides down with a rubber spatula. Remember that gluten-free bread doughs are always wetter than gluten doughs. It should be more like a thick cake batter, slightly sticky to the touch, than a finished gluten dough would be. See photo of it here.)

Once you have scraped the dough down into a one ball, shape it with damp hands into one coherent dough. (See photo of that here.) Put it in a lightly oiled bowl. Cover the dough with plastic wrap or a damp towel and allow it to sit in a warmish place in the kitchen until it has risen to twice its size, about 2 hours.

Baking the hamburger buns. About 1 1/2 hours after you have set the dough to rise, preheat the oven to 425 degrees. If you have a pizza stone (and boy, does it help with gluten-free baked goods), put it in the oven to come to temperature. Line a baking sheet with parchment paper or a Silpat. When the oven is fully hot, take the dough out of the bowl. It should feel good in your hands, like a traditional bread dough. (If it’s sticky, because you let the sponge grow for longer than 2 hours, simply wet your hands and work with the sticky dough.) If you want small buns (like sliders), cut the dough into 8 pieces. If you want larger hamburger buns, divide the dough into 5 pieces. Roll each piece of dough under your hands until it feels like a good ball of dough. Place it on the baking sheet and flatten it just a bit with the palm of your hand.

If you wish, brush the top of each dough ball with the beaten egg, then sprinkle with the sesame seeds.

Put a large sheet tray into the bottom rack of your oven. Fill it 1/2 way full with water. (I pour it from the tea kettle.) Slide the sheet tray with the dough on top of the pizza stone (or on a middle rack, if you don’t have a pizza stone). Spray the inside walls of the oven with water from a clean spray bottle. Close the oven door. Wait 30 seconds. Do it again. Bake the hamburger buns until they are golden brown, give a good hollow thump on the bottom, and have reached an internal temperature of 180 degrees (but no higher). This should take about 15 to 25 minutes, depending on the size of the buns you make and your own oven.

Source: http://glutenfreegirl.com/2010/06/gluten-free-hamburger-buns/