Preheat your oven to 430°F (220°C). Toss diced sweet potatoes and minced garlic with olive oil, salt, and pepper in a mixing bowl. Spread on a baking sheet and roast for 20-25 minutes, stirring halfway through.

Boil salted water in a large pot. Add short pasta and cook until al dente, about 8-12 minutes. Reserve 2/3 cup of cooking water, then drain pasta.

Heat a tablespoon of olive oil and unsalted butter in a skillet over medium heat. Fry sage leaves for 1-2 minutes until crispy, then remove and drain on paper towels.

In the same skillet, mash half of the roasted sweet potatoes with a fork, adding garlic for flavor. Warm everything together.

Add the drained pasta to the skillet. Pour in heavy cream and goat cheese, tossing over medium heat. Gradually add reserved pasta water to achieve the desired creamy sauce consistency.

Season the pasta with salt and pepper to taste. Serve topped with remaining roasted sweet potatoes, crispy sage, olive oil, and optionally Parmesan or red pepper flakes.