Toast pine nuts in a dry skillet over medium heat until all the nuts are slightly browned, about 2 minutes. Set aside.
Cook pasta according to package directions; drain.
While pasta is cooking, heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Add carrots; cook for 30 seconds while stirring. Add zucchini and squash; cook, stirring, until tender, about 3 minutes. Remove vegetables from skillet.
Add remaining oil to skillet; stir in flour until absorbed. Stir in the half-and-half and tomato paste. Cook, stirring, until mixture comes to a boil and thickens. Stir in pasta and vegetables. Cook, tossing, until heated through. Remove from heat and stir in cheese and add salt an