Remove crust from oven. Top with marinara sauce and sprinkle with crushed red pepper and mozzarella. Remove broccoli rabe from oven and add to top of pizza. Return pizza to bottom rack and bake until cheese melts and crust is dark golden brown, 5 to 8 minutes. Let cool for 5 minutes. Sprinkle with pecorino Romano and, if desired, drizzle with hot honey.