Make the gnocchi

1. Place the squash cubes in a pot of boiling water and cook until very tender, about 10–15 minutes. Drain well and let the pieces cool slightly.
2. Mash the squash into a smooth puree in a large bowl. Season lightly with salt and pepper.
3. Add the egg to the squash, then stir in the flour a little at a time until a soft dough forms. Don’t overwork it — you want a pliable, slightly tacky dough.
4. On a lightly floured surface, roll the dough into long ropes about ¾–1 inch thick. Cut the ropes into bite-sized pieces. If you like, press each piece gently with a fork to create ridges.
5. Bring a large pot of salted water to a boil. Cook the gnocchi in batches; they’re done when they float to the surface. Scoop them out with a slotted spoon and set aside.

Prepare the creamy sauce

1. In a saucepan over medium heat, melt the butter. Add the minced garlic and sauté briefly until fragrant — about 30 seconds.
2. Pour in the heavy cream and bring it to a gentle simmer. Stir in the grated Parmesan and continue stirring until the sauce thickens slightly and becomes smooth. Season with salt and pepper, then remove from heat.

Cook the sausage

1. Heat the olive oil in a skillet over medium heat. Add the diced onion and cook until soft and translucent.
2. Add the sausage, breaking it up with a spatula, and cook until nicely browned and cooked through. Stir in the minced garlic and the red pepper flakes, if using, and cook another minute to bloom the flavors.

Assemble and serve

1. Toss the cooked gnocchi with the warm Parmesan cream so each piece is evenly coated.
2. Plate the gnocchi and spoon the browned sausage mixture over the top.
3. Finish with a sprinkle of chopped fresh parsley and extra grated Parmesan, if desired.