Before starting this recipe, go read the whole post and look at all of the step by step photos. This recipe can be tricky so please do this first so you understand the steps.
Add the yeast, sugar, and warm water and allow it to sit for 5 minutes until frothy. Note I highly recommend using filtered water to rise your yeast.
Add the melted butter, sugar, levain (optional), and egg to the yeast mixture. Mix well then add the gluten free flour. Pour in an additional ¼ cup of water. Mix into a wet dough.
Cover the bowl with plastic wrap and allow to rise for 2 hours. I let mine rise overnight.
Add more flour (the amount really depends on what gluten free flour blend you use and how starchy it is.) You want your gluten free crescent roll dough to be workable.
Place the dough on gf flour dusted wax paper and cover it with another piece of wax paper. Roll to 1-inch thickness. Allow it to rise in the refrigerator for 1 hour. While the dough is rising/resting, take out the butter and put it on the counter so it can warm a bit.
Remove the dough from the refrigerator. Dust with flour and roll it out to ½ inch thickness. Try to roll it into a more rectangular shape.
Put your softened butter between two pieces of wax paper and roll it to ¼ inch thickness. Try to match the shape of the dough.
Place the butter onto the dough. Center it.
Fold your dough over the butter on all sides. Dust the flour with gluten free flour liberally so it doesn't stick.
Press the dough closed, wrap it in plastic wrap, and refrigerate for 1-2 hours. I refrigerated mine overnight but you don't have to rest it for that long.
Remove the dough from the refrigerator. Allow the dough to warm on the counter for 20 minutes. Roll the dough thin. Try to keep it in a rectangle shape.
Fold the dough into a tri-fold. Pull one side halfway up to the middle, then pull the other side up to that end. It will make a small rectangle shape that looks like Step 10. Refrigerate the folded dough for 30 minutes. Remove and let it sit out for 15 minutes. Roll to a thin large rectangle and fold again
Repeat this folding/rolling step 2-3 more times refrigerating the dough for 30 minutes between steps. This will really help thin and disperse the butter into the dough.
After repeating the rolling folding steps several times, lay your dough on a piece of flour dusted wax paper. Use a pizza wheel or knife to cut the dough into triangles. My dough was a bit sticky. It is okay to dust with flour lightly if this happens.
Start at the wide end and roll your dough towards the narrow end. Place the roll onto a parchment paper-lined cookie sheet. Use a cookie sheet with sides in case some butter melts out of the dough!
Repeat until you roll all of the dough into crescents. Cover in plastic wrap and let sit and allow to rise for 1 hour.
Preheat the oven to 375º F. Mix an egg, cream, and salt in a cup and use a pastry brush to egg wash all of the gluten free crescent rolls.
Bake the crescent rolls for 15-20 minutes depending on their size. You will know they are ready when they are golden.