into disks, cover in plastic wrap and chill while preparing filling. to prepare filling: in a bowl of an electric mixer on medium speed, beat butter, brown sugar, cinnamon and salt until smooth. remove 1 dough disk and place on a piece of waxed paper dusted with powdered sugar*. roll or press dough to a 9- by 12-inch rectangle dusting with additional powdered sugar to prevent sticking. dot teaspoon-size pieces of filling over half of dough (using half of filling) and use the back of a spoon to evenly spread filling across top of dough. beginning with 1 long edge, gently roll up dough, peeling away bottom layer of paper 