Over medium heat boil yuca in salted water until tender, approximately 20 minutes. Make sure not to overcook. Drain yuca and remove the stringy center portion. In a small skillet cook scallions and garlic in 1 tablespoon olive oil until fragrant, approximately 3 minutes; then set aside to cool.
In a food processor place eggs, parsley, baking powder and sauteed scallion and garlic mixture. Puree until smooth then season to taste with salt and pepper. Allow it to cool then add the yuca and puree all together. In a small skillet heat 2 tablespoons oil and saute red onion, vinegar and oregano for 5 minutes until soft. Season to taste with salt and pepper and set aside to cool.
Bring the yuca mixture to room temperature. In a heavy bottom skillet heat 2 to 3 inches of oil to 375 degrees. Shape batter in an ice cream scooper and fry the fritter until golden. Place fritters on towel. Season with salt and pepper.
Arrange fritters on a serving platter and top each fritter with a little pickled red onion on top.