1-Mix flour, baking powder, and salt in a medium bowl.

2-Beat butter and sugar on high speed until creamy (about 2 minutes), then add egg and vanilla and combine.

3-Gradually add dry ingredients to wet, mixing on low until combined; dough should be slightly soft. Add 1 tablespoon flour if too sticky.

4-Divide dough in half and roll each into a 9×7 inch rectangle about 1/4 inch thick on a floured silicone mat or parchment paper.

5-Spread 1 tablespoon melted butter on each rectangle, then evenly sprinkle with sugar and cinnamon mixture.

6-Tightly roll each rectangle into a 9-inch log, smoothing cracks with fingers.

7-Chill logs in the refrigerator for at least 2 hours or freeze up to 3 months.

8-Preheat oven to 350°F (177°C) and line baking sheets with parchment or silicone mat.

9-Slice logs into 1/2 inch rounds, spacing them 2 inches apart on baking sheets.

10-Bake for 10-11 minutes until edges are lightly browned. Cool on sheet for 5 minutes, then transfer to wire rack.

11-Combine icing ingredients and drizzle over cooled cookies.

12-Store covered at room temperature up to 5 days.