In a large skillet, cook bacon over medium heat until crispy. Drain on paper towels and crumble once cooled. Set aside. Preheat oven to 375°F (190°C).

In a large mixing bowl, combine the softened cream cheese, sour cream, and mayonnaise. Beat with an electric mixer or whisk until smooth and well combined.

Stir in the ranch seasoning mix, garlic powder, onion powder, and black pepper until fully incorporated.

Gently fold in 1.5 cups of shredded sharp cheddar cheese, 0.75 cups of shredded Monterey Jack cheese, 3/4 of the crumbled bacon, and 1/4 cup of the chopped green onions into the cream cheese mixture. Reserve the remaining cheese, bacon, and green onions for topping.

Spread the dip mixture evenly into a 9x13 inch baking dish. Sprinkle the remaining 0.5 cups of sharp cheddar cheese and 0.25 cups of Monterey Jack cheese over the top.

Bake in the preheated oven for 20-25 minutes, or until bubbly and the cheese on top is melted and lightly golden.

Remove from oven. Garnish with the remaining crumbled bacon and chopped green onions. Serve warm with your favorite dippers like crackers, pretzel crisps, celery sticks, or tortilla chips.