Combine the warm water and sugar in a large mixing bowl, then stir in the yeast and allow the mixture 5-10 minutes to proof and get foamy.
Combine the oil, buttermilk, egg, and salt in a large liquid measuring cup, add the mixture into the mixing bowl, and stir to combine.
Add 2 cups of flour to the mixture, and stir on low speed (with a dough hook attachment) until incorporated.
Continue to add flour, ¼ cup at a time, until the dough pulls away from the sides of the bowl and looks clean.
Increase the speed to medium and knead for 5 minutes, or until the dough sticks to itself but not to your fingers.
Place the dough in a large, lightly oiled bowl (I used non-stick spray), and cover with plastic wrap. Allow it to rise, in a warm place, for at least 2 hours or up to overnight in the fridge.
When the dough has doubled in size, roll into a (horizontal) rectangular shape about ⅛-inch thick, and top with an even layer of filling, leaving a one inch margin on the edge furthest from you.
Carefully roll (away from you) into a long log, sealing with the bare margin.
Cut into 8 equal rolls, and place in a cast iron skillet. Cover with plastic wrap and allow to rise for one hour, or until doubled in size.
Bake in a preheated 350 degree oven for 25 minutes, or until puffed and lightly golden on the top.
Cool completely, and drizzle with Milk Chocolate Glaze.