Heat the oil in a large pot until it reaches 350˚F (120˚C).
In a small bowl, combine the flour, garlic powder, onion powder, thyme, cayenne, paprika, salt, and pepper, and mix until evenly distributed. Dredge the pickles in the flour mixture, then the eggs, and then the bread crumbs. Fry the pickles for 3 to 5 minutes, or until browned and crispy on the outside.
For the ranch dressing, add the buttermilk, mayonnaise, sour cream, garlic powder, onion powder, dill, parsley, salt, and pepper to a medium bowl and stir until well combined.
Using a toothpick, assemble a slider by layering a fried pickle, the ranch dressing, a meatball, lettuce, a tomato slice, and one more pickle. Repeat with the remaining ingredients.