Bring a large pot of salted water to a boil. Cook the fusilli until al dente.
While the pasta cooks, heat a generous glug of olive oil in a wide sauté pan over medium heat until fragrant. Cut the heat and add the seeded, diced Campari tomatoes, a pinch of salt, and the chopped roasted garlic. Cover and let the mixture sit for 15 minutes, allowing the tomatoes to soften into a chunky, fresh sauce.
Add the drained pasta to the pan with the tomatoes and garlic. Toss over medium heat to combine, about one minute.
Off the heat, stir in the pesto. Taste and adjust seasoning with salt and pepper. Add the bocconcini to each portion individually and serve immediately —they should soften slightly from the residual heat but not fully melt.
Garnish with extra virgin olive oil, torn basil, chili flakes, or a dusting of cheese, if desired.