In a medium mixing bowl, combine the softened cream cheese, sour cream, mayonnaise, garlic powder, and onion powder. Using a hand mixer or spatula, blend until the texture is completely smooth.
Fold in 1/4 cup of the cooked bacon crumbles and 1/2 cup of the shredded cheddar cheese into the cream base.
Transfer the mixture to a 9-inch glass pie plate or shallow serving dish, spreading it into an even layer with an offset spatula.
Distribute the shredded iceberg lettuce evenly over the top of the cream cheese base, leaving a small margin at the edges for visual presentation.
Layer the diced tomatoes over the lettuce, followed by the remaining shredded cheddar cheese and the remaining bacon crumbles.
Top the dish with sliced green onions as a garnish.
Cover and refrigerate for a minimum of 30 minutes to allow the flavors to meld before serving.
Serve chilled with sturdy crackers, pita chips, or toasted baguette rounds.