Preheat oven to 500 degrees F and place the pizza stone on the bottom rack.
Crumble the yeast in a small bowl then add 1/4 cup of warm water and the syrup. Stir together and leave for 5 minutes to dissolve.
Put the flour and salt in a mixer fitted with a dough hook and give it a quick spin to mix. Pour in the yeast mixture, the remaining warm water and the olive oil at the same time, see Cook's note*.
Spin on low until the flour and water come together and the dough pulls away from the sides of the bowl. Put the ball of dough in a large bowl and drizzle a few drops of olive oil on top to keep it from forming a skin as it proofs. Cover with a towel and leave in warm place for 30 minutes to let the dough proof. When the dough has proofed it will double in size and look spongy.
For the topping: Caramelize the onions in a frying pan over low heat with a little olive oil and one of rosemary sprigs. When the onions are golden season with sea salt and black pepper and a few drops of lemon juice to bring out the flavor.
When the dough has proofed, roll it out onto to a floured surface and punch the air out with your hands, then start shaping it into a circle When it's stretched out, dust a pizza paddle with flour and place the dough on it.
Cover with a generous splash of olive oil and scatter with pieces of Robiola. Shingle the pancetta slices around and add the caramelized onions, and the stripped needles of the remaining rosemary sprig. Drizzle with olive oil. Add salt and black pepper.
Slide the pizza onto the stone in the oven (be careful the stone is 500 degrees F) and bake for 15 minutes. Shave white truffles over it. Eat immediately.