Boil a large pot of salted water over high heat, add the macaroni and cook for about 7 minutes until al dente. Strain and rinse under cold water.

In a medium saucepan, heat the heavy cream over medium heat until it simmers. Gradually mix in Gruyere, Gorgonzola, Parmesan, and pumpkin puree until smooth.

In a skillet, heat olive oil, add apple chunks, and sauté for about 5 minutes. Season with salt, pepper, cinnamon, and nutmeg.

Combine the cooked macaroni, cheese sauce, and sautéed apples in a large bowl, folding until well coated.

Preheat oven to 350°F (175°C). Grease a baking dish, pour in the mixture, top with breadcrumbs, cheddar, and rosemary.

Bake for 15–20 minutes until the top is golden brown. Let sit before serving.