Preheat the oven to 350F line baking sheets with parchment paper.
In a medium bowl, whisk together the flour, baking powder, and aslt to combine.
In a large bowl, use an electric mixer on medium-high speed to beat the butter and 1/4 cups sugar until light and fluffy, 2 to 3 min. Add the egg, egg yolk, and vanille, and beat untilc ombined. Slowly beat in the flour miture.