Fill a large pot with water, add a generous pinch of salt, and bring it to a boil. Add 12 ounces of rotini pasta and cook according to package instructions until al dente, usually about 8-10 minutes. Drain the pasta in a colander and set aside, reserving about 1/2 cup of pasta water.
While the pasta cooks, heat 2 tablespoons of olive oil in a large skillet over medium heat. Add the minced garlic and sauté for about 30 seconds until fragrant. Add 1 pound of ground turkey, breaking it apart with a wooden spoon. Cook until browned and cooked through, about 5-7 minutes. Season with salt and pepper.
Reduce heat to low. Pour in 1 cup of heavy cream and 1/2 cup of pesto sauce, stirring to combine with the browned turkey. Let the mixture simmer gently for 3-4 minutes to thicken, stirring occasionally.
Add the cooked rotini to the skillet, tossing gently to coat every piece in the creamy pesto sauce. If the sauce seems too thick, add reserved pasta water a tablespoon at a time until you reach your preferred consistency.
Turn off the heat and stir in 1/2 cup grated Parmesan cheese until melted and fully incorporated. Taste and adjust salt and pepper if needed. Serve immediately, garnished with fresh basil leaves for a vibrant finish.