Peel the yuca and cut into 1 ½" [3.8 cm]-thick pieces.Place in a deep pot, pour in 2 qt [2 lt] of water, add the salt and boil over medium heat until it is very tender (10-15 mins).
2. Mash yuca
Remove the yuca from the water, remove the central nerve (careful not to burn your fingers), and mash until there are no lumps. Mix in egg yolk, butter, parsley and garlic powder.Let the mixture cool to room temperature, it should be firmer then.
3. Make the balls
Cover your hands with oil to prevent the yuca mixture from sticking to them. Place 1.5 teaspoons of the mixture on the palm of your hand and flatten.Put a cheese cube in the center and wrap the yuca mash around it making sure the cheese is not poking through the yuca. Freeze for an hour.
4. Bake the balls
Heat the oven to the maximum temperature it can reach, if your oven has a broiler function, it's better to use that. Place the balls on a mini-muffin tray, or mini paper cups (see notes).Bake the balls until they turn a light golden color.
5. Serving
Let it cool for a few minutes before serving.
Notes
Some of the balls will inevitably leak cheese, they stand a much better chance if baked in a mini-muffin mold, or mini-paper cups. Most will come out OK if you make sure that the cheese is completely surrounded with yuca.To make them in the air fryer it is the same procedure, but heat the air fryer at the same temperature and cook for 15 minutes, or until they get a light golden color. Make sure to line the bottom with parchment paper because these balls are very sticky.