Prepare the Spicy Pesto:

1. Toast the Pine Nuts: In a dry skillet over medium heat, toast the pine nuts for 2-3 minutes until golden brown and fragrant. Remove from heat and let cool.
2. Blend the Ingredients: In a food processor, combine basil leaves, toasted pine nuts, garlic, Parmesan cheese, red pepper flakes, and cayenne pepper (if using). Pulse until finely chopped.
3. Add Olive Oil: While the food processor is running, slowly drizzle in the olive oil until the mixture forms a smooth, creamy pesto. Season with salt and black pepper to taste. Set aside.

Cook the Cascatelli:

4. Boil the Pasta: Bring a large pot of salted water to a boil. Cook the cascatelli according to package instructions until al dente. Reserve ½ cup of pasta water before draining.

Roast the Cherry Tomatoes:

5. Prepare the Tomatoes: Preheat the oven to 400°F (200°C). Toss the cherry tomatoes with 1 tablespoon of olive oil and a pinch of salt.
6. Roast the Tomatoes: Spread the tomatoes on a baking sheet and roast for 10-12 minutes until they are slightly caramelized and softened.

Combine and Serve:

7. Mix the Pasta and Pesto: In a large mixing bowl, toss the cooked pasta with the spicy pesto. If the sauce is too thick, add a splash of reserved pasta water to loosen it.
8. Add the Roasted Tomatoes: Gently fold in the roasted cherry tomatoes.
9. Garnish and Serve: Transfer the pasta to serving plates, garnish with additional Parmesan cheese and a sprinkle of red pepper flakes, and enjoy!