This mac 'n' cheese is perfectly creamy with a smoky bacon flavor, yet the slight sweetness from the roasted squash still shines through. One of my favorite parts is that it doesn't bake in the oven forever -- just broiler kissed on top. —perrysplate
uncooked elbow pasta (or other small pasta)
Bring a large salted pot of water to boil. Add pasta and cook for a couple minutes short of the package directions. Reserve about 2 cups of pasta water.
Meanwhile, cook bacon in a large oven-safe skillet over medium heat until crisp. Remove bits with a slotted spoon and set aside. At this point, you can either leave all of the bacon drippings in the pan, remove some, or replace it entirely with about as much cooking oil. It's up to you. I left all of the bacony goodness in the pan. If you replace it with cooking oil, make it nice and hot before moving on to the next step.
Turn on the broiler and move a rack to the upper third of your oven.
Add flour to the skillet and stir until it forms a loose paste. Let it cook at medium heat for about a minute or until it gets bubbly. Add milk, smashed squash, smoked paprika, lemon pepper, and salt to the skillet. Cook, stirring, until mostly smooth. Continue to cook, about 5 minutes or so, until the sauce begins to thicken and bubble.
Reduce heat to medium-low and add yogurt and shredded cheese. Stir until the cheese is melted and mixture is smooth.
Remove from heat. Add chopped spinach, cooked pasta, and enough pasta water to create the thickness you prefer. Keep in mind that the mixture with continue to thicken later as it cools.
Sprinkle reserved bacon bits and green onions over top. Place in the oven and broil for about 5-7 minutes until top begins to bubble and turn golden.