Knead the dough ingredients together well, maybe add a pinch of salt. Baking powder is not necessary here. Then chill in the refrigerator for at least 30 minutes.
Preheat the oven to 180 °. Then press the dough evenly with your hands into a greased tart or fruit base tin or lined with baking paper and prick several times with a fork to avoid bubbles. Pre-bake for 10 minutes.
For the topping, mix all the ingredients together with the whisk, carefully so that the berries do not break. Then pour onto the pre-baked shortcrust pastry and bake everything again for about 25 minutes, depending on the oven.
The tart is very thin and can be removed as soon as the desired degree of browning is achieved. However, the mass must be thickened in the middle so that everything is cooked.
Looks wonderful with the blueberries, which burst easily when baking, and tastes good as a dessert or with coffee!