Mix the cinnamon and sugar in a small bowl and set aside. In a large mixing bowl, beat the butter and cream cheese until thoroughly whipped; about 30 seconds on medium if using an electric mixer. Add 1 cup sugar and the baking powder. Beat in the egg and vanilla. Beat in the flour last. Divide the dough in half. Roll one half between two sheets of wax paper into a 12x8 rectangle. Remove the top wax paper and brush dough with melted butter. Then sprinkle 2 tablespoons of cinnamon/sugar mix on top, dusting evenly. Roll the dough up like a jelly roll, removing wax paper. Seal the edges, then repeat with the other half. Chill the rolls for 4 hours wrapped externally in wax paper. After chilled, cut into 1/4-inch slices and bake at 375º F for 8-10 minutes, 1 inch apart. Cool on the sheet for 1 minute, then transfer to wire rack.
NOTE: Make sure that the rolls have as few cracks as possible, because cracks will become permanent after baking, and they spoil the swirl effect if you are going for a pretty and festive cookie.