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).
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.
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.
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.
Let it cool for a few minutes before serving.