First Step
Beat up 1/2 cup of melted butter, 1/2 cup of brown sugar and 1/4 cup of sugar.
Second Step
Add the egg and 1 tbsp of vanilla. Whisk it very well.
Third Step
Add 1 1/2 of all-purpose flour and mix it without over-beating the batter.
Fourth Step
Grab a pan with parchment paper. Place the batter with a spoon on the pan.
Fifth Step
Bake it in a prehated oven at 180° for 15 minutes. Let them chill, and ready!