Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a large mixing bowl, whisk together flour, baking powder, salt, and ground cinnamon.

In a separate bowl, cream together unsalted butter, granulated sugar, and brown sugar for about 3 minutes until light and fluffy.

Add the egg and vanilla extract to the creamed mixture, mixing until smooth.

Gradually add in the dry mixture, mixing on low speed until just combined.

In a small bowl, combine brown sugar and ground cinnamon for the filling.

Spread half of the dough onto parchment paper in a rectangular shape and sprinkle the filling evenly over it.

Roll the dough tightly into a log shape, ensuring the filling is inside, and repeat with remaining dough.

Slice each log into 1-inch rounds and arrange on the prepared baking sheet.

Bake for 10-12 minutes until edges are golden brown. Watch them closely.

Transfer cookies to a wire rack to cool completely before serving.