Heat oven to 375°F.
In small bowl, whisk together flour, baking powder and salt.
In a large mixing bowl, beat butter until creamy. Gradually add vanilla sugar; beat until light and fluffy, about 2 minutes. Beat in egg and vanilla extract; mix until smooth, scraping down side of bowl. On low speed, beat in flour mixture until combined.
Drop dough by heaping teaspoonfuls onto an ungreased baking sheet, spacing 2 inches apart.
Bake at 375°F for 10 minutes, or until edges are lightly browned. Let cool on sheets 1 minute, then remove to wire rack to cool completely.