Preheat oven to 375°.
Spray a 9X13 pan with non-stick spray.
In a large bowl, whisk together Bisquick, buttermilk and 4 Tbs. sugar. Dough should be a little sticky. Add more buttermilk if necessary. In a small bowl, whisk together brown sugar, 1 cup white sugar and cinnamon. Stir in 2 Tbs. melted butter to moisten.
Generously flour an area to roll out dough. Turn out dough and form a ball. Roll into a 1/2" thick rectangle.
Spread remaining soft butter over dough and sprinkle evenly with cinnamon mixture. Gently press into dough.
Start rolling into a log from the long end. Gently roll "log" to seal seam.
Cut into 12 even slices.
Place tightly into prepared pan. Bake for 20 - 30 minutes until golden brown.