Preheat your oven to 400°F (200°C).

Pierce sweet potatoes multiple times and roast for about 45–60 minutes until tender.

Allow the sweet potatoes to cool, cut in half and scoop the flesh into a bowl.

Mash the cooled sweet potatoes until smooth.

Mix sweet potato mash, egg yolk (if using), salt, and flour until a slightly sticky dough forms.

Place the gnocchi dough in a piping bag or use a spoon to create small pieces.

Boil a large pot of salted water, drop gnocchi pieces in, and cook until they float (2-3 minutes for fresh, 4-5 minutes for frozen).

Scoop gnocchi out and pan-fry in olive oil until golden brown.