Beat eggs, sugar and vanilla sugar until whitish and frothy. First stir in the oil, then fold in the lemon juice and then the yogurt and zest. Mix the flour, baking powder and salt, sift into the egg mixture and stir in only briefly until nothing is visible. Then just as quickly and quickly fold in the colored pearls (otherwise they will lose their color), fill the dough into the pan and slide them into the oven on the 2nd rail from below. After 30 minutes of baking time, switch the temperature down to 180 ° and bake for another 10 minutes. Do the wooden stick test. No dough should stick to it when it is pulled out, otherwise the baking time should be extended by 5 - 6 minutes. Then leave the finished cake in the oven for 10 minutes with the door tilted (pinch a wooden trowel).