Place the riced cauliflower in a large microwave-safe bowl and microwave on high for 2–3 minutes, until tender.
Drain the cauliflower thoroughly, pressing out as much moisture as possible with a clean towel or fine mesh strainer, then transfer to a large mixing bowl.
Add the almond flour, egg yolks, and grated Parmesan to the cauliflower and stir until combined.
In a separate microwave-safe bowl, melt the shredded mozzarella (about 30–60 seconds, stirring as needed) and then pour it into the cauliflower mixture.
Mix thoroughly until the melted cheese is fully incorporated and a cohesive dough forms. If sticky, wet your hands slightly to help shape.
Divide the dough into 4 equal portions and roll each portion into a ball. Place the balls on a plate, cover, and refrigerate for 10 minutes to firm up.
Lightly dust a work surface with almond flour. Roll each chilled ball into a thin log, then slice into bite-sized pieces. Press each piece gently with a fork to create ridges.
Place the shaped gnocchi on a plate, cover, and refrigerate for 20 minutes to firm before cooking.
Bring a large pot of salted water to a boil. Add the gnocchi and cook for about 1 minute, until they float and are heated through.
Use a slotted spoon to remove and drain the gnocchi, then serve with your favorite pasta sauce.