Preheat your oven to 350°F (175°C). Peel and dice the yellow potatoes into small, bite-sized pieces.

In a large mixing bowl, combine the diced yellow potatoes with chopped yellow onion, minced garlic, and mayonnaise. Add 2 cups of cheddar cheese, crumbled bacon, onion powder, garlic powder, salt, and black pepper. Stir until well-coated.

Transfer the potato mixture into a greased 9x13 inch baking dish, spreading it out evenly. Cover tightly with aluminum foil.

Bake covered for 45 minutes until fork-tender.

Remove the foil and sprinkle the remaining ½ cup of cheddar cheese on top. Bake uncovered for an additional 15 minutes until cheese is melted and golden brown.

Let it rest for 5 minutes, then garnish with freshly sliced green onions before serving.