Place balsamic in a small pot on medium-high. Let simmer until reduced and noticeably thick. Remove from heat and let cool. Sauce will continue to thicken as it sits.
Preheat oven to 500°F. Grease a pizza pan with olive oil or dust with cornmeal.
On a floured surface, roll out your dough. Transfer to prepared pan.
Rub dough with enough olive oil to coat the surface evenly.
Crumble/spread chèvre over dough. Top with nectarines and Parmesan.
Bake in preheated oven for 10 minutes, or until the crust is slightly brown and the cheese is melting.
Remove from the oven and sprinkle with fresh basil. Drizzle with the reduced balsamic. Slice and serve warm.