Make the swirl. Mix butter, brown sugar, and cinnamon, then load into a bag with a small corner cut. Make the glaze. Beat cream cheese and butter, then add powdered sugar, milk, vanilla, and salt until thick.
Combine the dry. Whisk flour, baking powder, baking soda, salt, and sugar. Combine the wet. Whisk buttermilk, egg, butter, and vanilla.
Fold and rest. Mix just until moistened and rest 5 minutes.
Preheat. Warm a buttered griddle over medium heat and the oven to 200 degrees F.
Pour and pipe. Pour 1/3 cup batter, pipe a spiral on top, and cook 2 1/2 minutes until bubbles appear.
Flip and glaze. Flip swirl side down, cook 1 to 2 minutes, then stack and spread with glaze.