Step-by-step cooking method Add the yeast to a bowl with water and stir thoroughly. In another bowl, mix the sugar and flour together. Add the eggs and water to the yeast from the first step and keep stirring. Add a little vanilla, stir and add the butter. Stir again. When the dough is ready and is no longer sticky, leave to prove for one hour. Sprinkle a little flour onto the kitchen worktop. Using a rolling pin, roll the dough out to a thickness of approx. 1cm. Use a cutter to shape the doughnuts. Cook the doughnuts in the fryer and turn them over so they cook properly on both sides. Add a little sugar on top of the doughnuts to serve.