Heat the milk: In a large pot, bring the milk to a gentle simmer over medium heat. Add sugar and a pinch of salt.
Prepare the dumplings: In a small bowl, combine flour with a little cold water to make a thick paste. You can also form tiny dumplings by hand or using a teaspoon.
Add dumplings to milk: Drop small spoonfuls of the flour mixture into the simmering milk. Stir gently to prevent sticking, but don’t overmix.
Cook: Let the dumplings cook for 8–10 minutes until they puff up slightly and are cooked through. Stir occasionally and watch carefully to avoid scorching.
Finish: Stir in butter and vanilla extract if using. Sprinkle with cinnamon or nutmeg before serving.
Serve: Serve warm in bowls, ideal for breakfast, an afternoon snack, or supper.