Preheat your oven to 350°F (180°C).
Cream the softened butter and sugar together until light and fluffy. Add the egg and vanilla extract. Mix until smooth.
In a separate bowl, whisk together the flour, baking powder, and salt. Gradually add the dry ingredients to the wet mixture and stir until a dough forms.
In a small bowl, mix together the brown sugar and cinnamon.
Scoop dough into tablespoon-sized balls. Roll each one in the cinnamon-sugar mixture, then place on a lined baking sheet.
Gently flatten the tops of each dough ball and drizzle with melted butter.
Bake for 10–12 minutes or until the edges are just golden. Let cool before devouring—or don’t, I’m not your mom.