1. Sift together ﬂour, baking powder, and salt.
2. In a separate bowl, beat eggs well; add sugar and vanilla extract and beat until thick.
3. Stir in the ﬂour mixture and then the jam, until smooth. Spread over crust.
4. Bake until puffed and dark brown, and a toothpick inserted comes out with soft, moist crumbs attached; about 40 minutes. (Be careful not to over-bake; it will be very dry.) Cool completely.
5. Sift confectioners’ sugar over bars and cut into small squares.