Preheat oven to 350 degrees. Spray a 1/2 sheet pan with non-stick olive oil spray.
Slice the Hawaiian buns in half horizontally with a serrated knife. If you can, keep attached. Lay each half of the buns cut side up on the prepared baking sheet. Spray with non-stick olive oil spray or brush with olive oil. Sprinkle with salt, pepper and 1/2 tsp oregano. Place in the oven and toast for 5 minutes or until light brown and toasted.
While the buns toast, if you haven't already shred the lettuce and finely chop the pickles and banana peppers. Toss the three ingredients together.
Remove the buns from the oven. Take the top buns off of the sheet pan and set aside for now. Layer the turkey on the bottom of the slider buns. Next, the ham. Layer six slices of provolone cheese on top. Cover with salami, followed by pepperoni. Place back in the oven for 5-6 minutes.
Remove the pan from the oven and put the side bun tops back on the pan cut side up. Cover with another layer of cheese. Place back in the oven and bake until the cheese is melted and the meat on the other side is hot and toasty.
While the sliders finish baking, make the dressing. Add mayo, red wine vinegar, banana pepper juice, dijon, sugar, remaining 1/2 tsp oregano, salt and pepper to a small bowl. Whisk to combine. Season to taste with salt and pepper.
When the cheese on the sliders has melted pull them out of the oven. Cover the bottom meat-covered half with the lettuce and pickle mixture. Drizzle with the dressing. Reserve extra dressing for dipping. Place the cheese-covered top bun on top of the sandwich. Slice and serve warm.