Microwave or bake purple sweet potatoes until tender, about 6-8 minutes in the microwave or 45 minutes at 400°F in the oven.

Let cool slightly, peel the skins off, and mash the flesh in a large mixing bowl until smooth.

Add all-purpose flour, Parmesan cheese, egg, and salt to the mashed sweet potato; mix until a non-sticky dough forms.

Divide the dough into four portions, roll each into a long rope, cut into ½ inch pieces, and roll against a fork for the classic indentations.

Boil a large pot of salted water; cook gnocchi in batches until they float, about 3-5 minutes.

In a skillet, melt butter over medium heat, add minced garlic and sage, sauté for 1-2 minutes until fragrant.

Add cooked gnocchi to the skillet; toss in the garlic butter sauce for 2-3 minutes until slightly crispy.

Plate the gnocchi with extra Parmesan cheese if desired and serve immediately.