In a mixing bowl, mix the flour with the yeast and a generous pinch of salt. Then add the water and mix until you have a very soft and sticky dough. Cover the let the dough rise for a good 2 or 3 hours, or more if convenient. When the dough has risen, it should have formed bubbles. It will also be quite gooey.
While the dough is rising, trim off the bottoms and tops of the zucchini, then shred them using the largest holes of a cheese grater. Place the shredded zucchini in a colander and sprinkle with salt. Let the zucchini rest.
When you're ready to fry, take the shredded zucchini in handfuls and squeeze them of their liquid. Pat the zucchini dry and add the shreds to the mixing bowl with the dough. Fold the zucchini into the dough with a spatula or your hands.
Heat abundant oil in a Dutch oven or deep fryer. When the oil reaches 180C/350F, start adding dollops of the dough using two spoons, one to scoop up a bit of the dough out of the mixing bowl and the other to slip the sticky dough off the first spoon and into the oil, taking care not to make too much of a splash. Repeat until you've used up all of the dough, working in batches if need be to avoid crowding the fritters. [NB: Be aware, the fritters will swell considerably as they cook.]
Deep fry the pasta cresciuta fritters until they are cooked through and lightly browned. Drain on a baking rack or paper towels and serve while they're still hot.