Preheat your oven to 350°F (175°C).

In a bowl, combine 2 cups of flour, baking powder, baking soda, and salt. Set aside.

In a separate large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.

Add the egg and vanilla extract to the butter mixture, mixing well until incorporated.

Gradually add the dry flour mixture to the wet ingredients, alternating with sour cream, starting and ending with the flour.

In another small bowl, mix together the cinnamon, brown sugar, and 1/4 cup of flour for the topping.

Scoop the cookie dough onto a lined baking sheet and sprinkle the cinnamon topping over each cookie.

Bake for 12-15 minutes or until the edges are lightly golden.

Allow to cool on the baking sheet for a few minutes before transferring to a wire rack.