Adjust rack to top position (top and middle positions for 4 servings) and preheat oven to 425 degrees. Bring a large pot of salted water to a boil. Wash and dry produce.

Cut broccoli into bite-size pieces if necessary.

Toss broccoli on one side of a baking sheet with a drizzle of olive oil; season with salt and pepper. Place bacon* on empty side of sheet. (For 4 servings, divide between 2 baking sheets; roast bacon on top rack and broccoli on middle rack.)

Roast on top rack until broccoli is tender and bacon is crispy, 15-20 minutes. TIP: If bacon is done before broccoli, remove from sheet and continue roasting broccoli.

Once bacon is cool enough to handle, chop into bite-size pieces.

Once water is boiling, add spaghetti to pot. Cook, stirring occasionally, until al dente, 9-11 minutes.

Reserve 1½ cups pasta cooking water (2 cups for 4 servings), then drain. Keep empty pot handy for the next step.

Once bacon and broccoli are done, heat pot used for pasta over medium heat. Add cheese roux and 1 cup reserved pasta cooking water (1½ cups for 4 servings); whisk to combine. Cook, whisking, until slightly thickened, 2-3 minutes.

Reduce heat to medium low and whisk in cream cheese.

Add drained spaghetti, garlic herb butter, and half the Parmesan (save the rest for serving) to pot with sauce. Toss until butter has melted and pasta is coated in a creamy sauce, 1-2 minutes. (TIP: If necessary, stir in more pasta cooking water a splash at a time.) Taste and season with salt and pepper.

Stir bacon and broccoli into pot with pasta.

Divide pasta between plates. Sprinkle with remaining Parmesan and serve.