To make the peanut sugar: Toast the crushed peanuts in a skillet over medium-low heat until slightly golden on the surface. Transfer to a bowl and freeze until completely cold. Pulse the cold peanuts and the sugar in a spice-grinder or food-processor until finely ground.
To make the dough: Microwave 1 ⅛ cups of water on high for about 30 seconds. Mix the warm water with 2 cups of bread flour and ¼ tsp of instant dry yeast and set aside for 20 min.
Prepare the butter: In a stand-mixer, mix the cold unsalted butter with all-purpose flour until thick but creamy. Transfer to parchment paper and set aside.
Switch to a dough-hook, add the flour/yeast/water-mixture, plus 2 ½ cups of bread flour, light brown sugar, salt, ½ tbsp of instant dry yeast and warm milk. Knead the dough until wet and sticky.
Dust the top of the dough with flour, press it down to shape it into a rectangle about 13" long × 10" wide. Roll it out length-wise to 33" long.
Scatter the butter over the dough-sheet, rub it into an even layer. Fold the dough 5 times over to create layers.
Turn the dough 90 degrees and roll it out again length-wise to 33" long, and fold 5 times again.
Place the square-dough on a well-dusted sheet pan, cover with plastic wrap and rest in the fridge for at least 2 hours.
Preheat the oven to 400ºF/200ºC. Roll the dough out into an 18" long × 10" wide rectangle. Sprinkle 1 cup of peanut sugar over the top, roll into a long log.
Cut the dough into 6 segments. Butter 6 large ramekins and coat with peanut sugar. Place each segment inside the mold, cover loosely and let proof for 30-45 min.
Bake in the oven for 30 min until golden browned and puffed. Remove from molds, let cool, then coat in peanut sugar and serve.