In a medium bowl, dissolve the yeast in the water with a pinch of sugar. Stir briefly, then let stand for 10 minutes until foamy.
Gradually stir the flour and salt. The dough should be soft, but not too sticky. Lightly dust your countertop with flour and transfer the dough onto it.
Knead the dough with your hands until the dough is smooth and elastic, about 3 minutes. If the dough is very sticky, knead in just enough flour, one tablespoon at a time, until the dough doesn’t stick to your hands.
Brush a medium bowl with melted butter, put the dough ball into the bowl. Cover, and let rest in a warm place for 1 hour.
Meanwhile, line a dinner plate with plastic wrap and set aside.
On a lightly floured countertop, roll the dough into a rectangle about 12″ x 18″ with the shorter sides to your left and right. The dough may be sticky and difficult to handle. Use a metal pastry scraper to coax the dough into shape, and a minimal sprinkling of flour, as necessary. (It will all be beautiful later, trust me.)
Distribute the cubed butter in the center of the dough and sprinkle with ¼ cup (50 gr) of sugar. Grab the left side of the dough, lift and fold it over the center, than do the same with the right side (like a letter). You should have what resembles a 3-level pastry.
Sprinkle the entire length of the dough with ¼ cup (50 gr) of sugar and (without rolling) fold again into thirds, as before.
Place on the plastic wrap-covered dinner plate and chill for 1 hour. (At this point, wipe excess flour from the countertop and dust the countertop with a rather liberal handful of sugar for rolling out the pastry again.)
Once chilled, remove dough from refrigerator. Ease it away from the plastic onto the sugar-covered countertop.(Use more sugar than shown. I was busy doing double-duty as the photographer and baker.)
Top the dough with ¼ cup (50 gr) of sugar, press it in a bit with your hands, and roll into a rectangle for the last time. Now wasn’t it easier this time?
Again, fold into thirds and let rest in the refrigerator for 30-60 minutes.
Preheat oven to 425° F (220° C) and brush a 9-inch (23cm) pie plate, preferably non-stick, with melted butter.
Remove dough from refrigerator. Roll dough into a circle about the size of the baking pan. It will be sticky; dusting the top with a sprinkle of sugar will help.
Once rolled, lift the dough and coax it into the pan. (It will want to break. If so, fold it in half and quickly slide something flat under it, like the metal bench scrape AND a metal spatula and quickly slip it into the pan. If it does break, just piece it back together in the pan.)
Sprinkle with the remaining ¼ cup (50 gr) of sugar and drizzle with 1 tablespoon melted butter.
Bake for 40-45 minutes, until the top is deeply caramelized. Let stand a few minutes, then run a spatula around the edges to release the Kouign Amann and slide the cake from the pan onto a cooling rack.
