Adjust rack to top position and preheat oven to 450 degrees. Bring a large pot of salted water to a boil. Wash and dry produce.

Cut butternut squash into bite-size pieces if necessary. Halve, peel, and thinly slice shallot. Peel and mince or grate garlic. Remove and discard any large stems from kale; chop into bite-size pieces.

Toss butternut squash on a baking sheet with a drizzle of oil, salt, and pepper. Roast on top rack, tossing halfway through, until browned and tender, 20-25 minutes.

Meanwhile, melt 1 TBSP butter (2 TBSP for 4 servings) in a large pan over medium heat. Add panko, salt, and pepper. Toast, stirring, until golden, 2-3 minutes. Transfer to a small bowl and set aside. Turn off heat; wipe out pan.

Once water is boiling, add cavatappi and cook, stirring occasionally, until al dente, 9-11 minutes. Reserve 1 cup pasta cooking water (1½ cups for 4 servings), then drain.

Heat a drizzle of oil in pan used for panko over medium-high heat. Add shallot and a pinch of salt; cook, stirring, until slightly softened, 2-3 minutes.

Stir in garlic and cook until fragrant, 30 seconds.

Reduce heat under pan to medium. Stir in kale and a splash of water; cook, stirring and adding more splashes of water as needed, until kale is tender and water has evaporated, 5-7 minutes.

Add cream sauce base, stock concentrate, and ¼ cup reserved pasta cooking water (⅓ cup for 4 servings) to pan with kale. Cook, stirring, until thickened, 2-3 minutes.

Remove pan from heat; stir in sour cream, Parmesan, and 2 TBSP butter (3 TBSP for 4) until melted and combined. Season with salt and pepper.

Stir drained cavatappi and squash into pan with sauce until thoroughly coated. TIP: If sauce is too thick, add more pasta cooking water and a drizzle of olive oil.

Divide pasta between plates and top with toasted panko. Serve.