Preheat the oven to 350°F (175°C). Line your baking sheet with parchment paper for easy cleanup.
Whisk dry ingredients: In a medium bowl, mix flour, baking powder, and salt until combined.
Cream butter and sugar: In a large bowl, beat the softened butter and granulated sugar until light and fluffy (about 2–3 minutes).
Add eggs and vanilla: Mix in one egg at a time, then stir in vanilla extract.
Combine: Gradually add dry ingredients to the wet mixture. Mix until a soft, cohesive dough forms. Avoid over-mixing.
Roll it out: Lightly flour your work surface and roll the dough into a rectangle about ¼-inch thick.
Make the filling: Stir together the melted butter, brown sugar, and cinnamon until smooth.
Spread and roll: Evenly spread the filling over the dough, leaving a small border. Roll tightly into a log, sealing the edge by pinching gently.
Slice: Use a sharp knife to cut ¼-inch rounds and arrange them on the prepared baking sheet, about 2 inches apart.
Bake: Bake for 10–12 minutes, until the edges are barely golden
Cool: Let cookies rest on the pan for 2–3 minutes, then transfer to a wire rack.
Glaze: Whisk powdered sugar, milk, and vanilla until smooth. Drizzle over cooled cookies and let set before serving.
Optional: sprinkle with cinnamon sugar or edible glitter for a festive finish.
