Heat oven to 350°F.
Line baking sheets with parchment.
Beat the 113 g softened butter, 67 g granulated sugar, and 25 g brown sugar until combined and creamy.
Add the 50 g beaten egg and 5 g vanilla. Mix until incorporated.
In a separate bowl, whisk together the 180 g flour, 4 g baking powder, and 1.5 g salt.
Add the dry ingredients to the butter mixture and mix just until no dry flour remains.
Divide dough into approximately 74g portions.
Roll each portion into a ball and place several inches apart on the prepared baking sheet.
Bake at 350°F for 10–12 minutes.
Melt 28 g butter in a small saucepan over low heat.
Whisk in 30 g powdered sugar.
Add 2 g vanilla and 10 g water. Stir until smooth and brushable.
Five minutes after removing the cookies from the oven, lightly brush the warm butter sauce over the tops.
Let the cookies cool completely.
Once cooled, dust lightly with powdered sugar.
