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

In a mixing bowl, combine the flour, baking powder, baking soda, salt, and cinnamon. Whisk together until well mixed.

In another bowl, cream the softened butter and brown sugar together using an electric mixer until the mixture is light and fluffy.

Add the egg and vanilla extract to the butter mixture and mix until fully combined.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined. The dough should be soft and slightly sticky.

In a small bowl, mix together the filling ingredients: brown sugar, cinnamon, and softened butter.

On a floured surface, roll out the cookie dough into a rectangular shape about ¼ inch thick. Spread the filling evenly over the dough.

Roll the dough up tightly from one end to the other to create a log. Slice the log into 24 equal pieces or rounds.

Roll each round in granulated sugar and place them on the prepared baking sheet, spacing them about 2 inches apart.

Bake in the preheated oven for 10-12 minutes or until the edges are lightly golden.

While the cookies are baking, prepare the glaze by whisking together powdered sugar, milk, and vanilla extract in a small bowl until smooth.

Allow the cookies to cool on the baking sheet for a few minutes before transferring them to a cooling rack. Once cooled, drizzle the glaze over the cookies.