In a mixing bowl, cream together softened butter and granulated sugar until light and fluffy, about 3-5 minutes. Add the eggs and vanilla extract, mixing until well combined.

Gradually blend in all-purpose flour, baking powder, and salt until a soft dough forms.

Divide the dough into two equal disks, wrap in plastic wrap, and chill in the refrigerator for about 30 minutes.

Roll out one disk of dough on a floured surface into a rectangle about ¼ inch thick. Brush with melted butter and sprinkle with cinnamon and brown sugar.

Roll the dough tightly from one long end into a log and repeat with the second disk of dough. Chill both logs until firm, about 30 minutes.

Preheat your oven to 350°F (175°C). Slice each log into ½ inch thick rounds, place on parchment-lined baking sheets, and bake for 10-12 minutes until edges are golden brown.

While cookies cool, prepare the icing by whisking together powdered sugar and milk until smooth. Drizzle over cooled cookies.