1. In a bowl, whisk together flour, baking powder, and salt.

2. In a separate bowl, cream the butter and sugar until light and fluffy.

3. Beat in the egg and vanilla extract.

4. Gradually mix in the dry ingredients to form a smooth dough.

5. On a floured surface, roll the dough into a ¼-inch thick rectangle.

6. Brush with melted butter and sprinkle evenly with brown sugar and cinnamon.

7. Gently press the filling into the dough, then roll it tightly into a log.

8. Wrap in plastic wrap and refrigerate for at least 1 hour.

9. Preheat oven to 350°F (175°C). Slice the chilled log into ¼-inch thick rounds.

10. Place slices on a parchment-lined baking sheet.

11. Bake for 10-12 minutes until edges are golden.

12. Cool for 5 minutes on the sheet, then transfer to a wire rack.

13. Mix powdered sugar, milk, and vanilla to make glaze.

14. Drizzle glaze over the cooled cookies and let set.