Creamy Pineapple Turnovers

For the crust, mix quark, salt, vanilla sugar, oil and milk. Add flour and baking powder to crust mixture and knead briefly to a dough. Cover dough and let stand briefly. For the filling, rinse and zest lemon. Finely dice pineapple. Mix quark, egg yolks, sugar, bourbon-vanilla sugar, lemon peel and pineapple. To assemble turnovers, roll out dough on a floured surface to a rectangle of 40 x 30 cm (approximately 16 x 12 inches) and cut into 12 squares of 10 x 10 cm (approximately 4 x 4 inches). Spread filling onto the center of each square, fold up corners over filling and squeeze to seal. Place turnovers on a baking sheet lined with parchment paper. Bake turnovers in oven preheated to 175°C (gas mark: 3)(approximately 350°F) for about 20 minutes.