Caramelized Onion, Ricotta, and Prosciutto Pizza Caramelize 1 sliced red onion and add 1 1/2 teaspoons golden brown sugar, 2 tablespoons balsamic vinegar, pinch of dried crushed red pepper. Smother fresh pizza dough with caramelized onion mixture. Top with ricotta and thin slices prosciutto. Bake at 500 for 10 min. After I take it out of the oven, I like to top it off with some arugula. YUM!