Place a large stock pot of water over high heat. As the water begins to boil, add a tablespoon of salt. Stir in the pasta and cook according to package instructions. When the pasta is almost al dente, drop the red peppers, snow peas, broccoli, and carrots into the boiling water to blanche for one minute. Then drain the pasta and veggies in a colander, reserving 2 cups of pasta water. Set the pasta water aside and rinse the pasta and veggies with cold water.
Using the same pot, place the pasta water, cream cheese, and garlic over medium heat. Bring to a simmer and whisk to create a thin smooth cream sauce. Once the sauce is completely smooth, add the pasta and blanched vegetables back to the pot. Stir well to coat the pasta.
Toss in the chopped scallions, raw zucchini slices, and thyme. Stir to incorporate. Taste, then season with salt and pepper as needed. Serve warm or at room temperature.
Keep leftovers in an airtight container in the fridge for up to 4 days.