Mix butter, brown sugar and white sugar.
Add in an egg and vanilla.
Mix again.
Add in flour, baking powder, and salt.
Mix until just combined. Don't overmix.
Make 2.5-3 tbsp size balls.
Bake at 350 degrees for 10-11 minutes.
Make butter sauce by melting 2 tbsp butter, then add ¼ c powdered sugar, 2 tsp water, ¼ tsp vanilla.
Let butter sauce sit for 5 minutes before brushing over semi-cooled cookies.
Dust cookies with powdered sugar.
