Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a medium bowl, whisk together flour, baking powder, cinnamon, and salt.
In a separate large bowl, cream butter with granulated sugar and brown sugar until light and fluffy.
Beat in the egg and vanilla extract until smooth.
Gradually mix dry ingredients into the wet mixture until just combined.
In a small bowl, prepare the filling by mixing brown sugar and cinnamon.
Roll half the dough onto parchment paper into a rectangle. Spread with filling mixture and roll tightly into a log.
Slice into ½-inch rounds and place on the prepared baking sheet.
Bake for 10–12 minutes or until edges are lightly golden.
Cool on a wire rack before serving.
