PREP: Preheat the oven to 350 degrees F. Generously grease a 9x13-inch casserole dish with nonstick spray and set aside. Bring a large pot of water to boil.
VEGGIE PREP: Trim the snap peas, peel and coin the carrot, thinly slice the mushrooms, peppers, and summer squash; halve the cherry tomatoes.
TORTELLINI: When the water boils, add 2 teaspoons salt. Prepare the tortellini according to package directions. In the last two minutes of boiling the tortellini, add in the sugar snap peas and carrots. Drain everything and then transfer to the prepared casserole dish.
SAUTE VEGGIES: Meanwhile, over medium-high heat, sauté the mushrooms, peppers, and summer squash in 2 tablespoons olive oil until crisp-tender, about 5 minutes. Pour over the tortellini, peas, and carrots in the casserole dish. Add the halved cherry tomatoes and frozen corn and gently toss everything to combine.
CREAM SAUCE: In a small pot, melt the butter over medium-heat. Once butter is melted, whisk in the flour to create a paste and cook for 1 minute. Gradually and slowly add in the broth and whisk until completely smooth. Gradually, while stirring constantly, add in the milk and whisk until smooth and thickened. Add in the garlic powder, salt, pepper, dried basil, and Italian seasoning. Stir. Meanwhile, soften the cream cheese (out of its package) in the microwave. Once soft, add into cream sauce and whisk briskly until completely smooth and melted. Taste the sauce and adjust seasonings adding more salt/pepper if needed.
BAKE: Pour the sauce over the veggies and tortellini. Stir gently in the casserole dish and then press into one even layer. Add Parmesan cheese on top. Bake for 20-25 minutes or until warmed through and cheese is melted on top. Broil for the last 1-2 minutes if desired. Enjoy hot! Lately, we've been enjoying this with a big scoop of pesto if there is some lingering in the fridge -- so good, but of course, totally optional.