Warm the milk slightly, then stir in the sugar and yeast. Let it stand for 10 minutes, until foamy.
In a large bowl, sift the flour, then add the salt, vanilla extract, lemon zest, and eggs.
Pour in the yeast mixture and mix until you have a smooth batter. Add the raisins and diced apple, if using.
Cover the dough with a clean kitchen towel and let it rise in a warm place for about 1 hour, or until doubled in size.
Heat the oil in a deep saucepan to approximately 350°F (180°C). If you don't have a thermometer, drop a small amount of batter into the oil – if it slowly rises and turns golden brown, the oil is at the right temperature.
Using a tablespoon or a small ice cream scoop, scoop small mounds of batter and carefully drop them into the hot oil.
Fry the oliebollen for 3-4 minutes, turning them occasionally, until they are evenly golden brown.
Remove the oliebollen with a slotted spoon and place them on paper towels to drain excess oil.
Sprinkle with powdered sugar while still warm, and serve immediately.
To provide the best experiences, we and our partners use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us and our partners to process personal data such as browsing behavior or unique IDs on this site and show (non-) personalized ads. Not consenting or withdrawing consent, may adversely affect certain features and functions.
Click below to consent to the above or make granular choices. Your choices will be applied to this site only. You can change your settings at any time, including withdrawing your consent, by using the toggles on the Cookie Policy, or by clicking on the manage consent button at the bottom of the screen.