Bring a large pot of water to a boil and add a heaping palmful of salt.

Heat a large 12” skillet over medium-high heat. Add a generous amount of olive oil to the bottom so that it comes about ⅛” up the sides. Once the oil is hot, add the sliced mushrooms in one even layer (work in two batches if needed). Allow the mushrooms to cook until golden and crisp, stirring often. Use a slotted spoon to transfer the mushrooms to paper towels. Season with a pinch of salt.

Meanwhile, drop the spaghetti in the boiling water. Cook for 1 minute less than the package’s instructions.

Wipe out the oil in the skillet and return to medium heat. Add the butter, honey, and rosemary. Allow the mixture to melt and come to a simmer. Reduce the heat to medium-low and simmer for about 2 minutes. Retrieve 1 cup of pasta water from the pot and add it to the honey mixture, whisking until combined. Bring to a simmer and cook for 2-3 minutes until the sauce has slightly reduced. Retrieve 1 more cup of pasta water and set aside.

Drain the pasta and add it to the skillet. Stir well. Add in the parmesan cheese, stirring until it melts into the sauce. As you stir, add splashes of pasta water if needed to keep the sauce silky smooth.

Stir in the mushrooms and allow to heat through. Season the pasta with salt to taste. Serve immediately with lots of parmesan cheese and freshly cracked black pepper over top.