Preheat oven to 375°F. Line 9x13 pan with parchment.
Press 1 tube of crescent roll dough into pan. Brush with butter & sprinkle brown sugar. Bake 8–10 min.
Beat cream cheese until smooth. Add sugar, egg, vanilla, sour cream. Spread over crust.
Mix swirl ingredients (brown sugar, cinnamon, butter). Drizzle over filling.
Place 2nd crescent roll sheet on top. Brush with butter. Bake 25–30 min.
Cool completely, at least 2 hours.
Mix glaze (powdered sugar, milk, vanilla). Drizzle on cooled bars. Cut & serve.