Preheat the oven to 350°F/180°C.
Using a hand whisk, mix eggs, oil, vanilla sugar, and brown sugar until a smooth brown mixture is obtained.
Gradually sift in white flour, whole wheat flour, and baking powder. Using your hands, knead everything together until a soft and uniform dough ball is obtained.
Roll the dough on a floured surface to ¼-inch (½ cm) thickness and cut circles using a cookie cutter.
Mix the jam with the cookie crumbs , so it does not spill out during baking.
Place a flat teaspoon of the filling in the center of each circle, pinch the edges together in three places so that they meet in the middle to form a triangular cookie shape, fasten, and arrange on a baking sheet lined with parchment paper. Don’t put in too much filling, or you won’t be able to close the hamantaschen. You do not want the filling to spill out.
Bake for 10-12 minutes until the bottom of the hamantaschen is slightly golden.
Let it cool and dust with powdered sugar.