-
Filling: Stir together the sugar and cinnamon; set aside.
-
Cookies: Cream the butter and brown sugar until well blended with an electric mixer on medium speed.
-
Add the eggs and vanilla; blend well.
-
Combine the flour, baking powder, salt, and cinnamon; add to butter mixture and blend well.
-
Turn dough out onto a sheet of waxed paper; spread into a 9x6-inch rectangle using a rubber spatula.
-
Sprinkle the cinnamon-sugar to within 1 inch from the edges.
-
Roll dough up jelly-roll style.
-
Roll in remaining cinnamon-sugar; wrap dough tightly in plastic wrap.
-
Refrigerate at least 4 hours.
-
Preheat oven to 350°F.
-
Slice dough 1/4-inch thick; place 2 inches apart onto parchment-lined cookie sheets.
-
Bake for 8 minutes or until golden on top.
-
Cool for 4 minutes on the cookie sheets, then remove to racks and cool completely.