In a skillet over medium high heat, add a small splash of the oil. Once hot, add the cubed chicken and cook until lightly browned, about 5 minutes. Stir in the cumin, chili powder, garlic powder, salt and pepper.
Next, stir in the pepper jack cheese, corn, black beans, bell pepper, onion, and cilantro. Stir and cook for 2 more minutes.
Add in the spinach and cook until wilted, 1 minute.
Add about 1/4 cup of filling to each egg roll wrapper. Wet the edges of the wrappers. Pull the sides in over the filling, then fold over the end of the wrapper and roll tightly. The wet edges should hold it together.
In another, large skillet, add the remaining cooking oil. Once it’s hot and shimmering, add a few eggrolls. Don’t crowd them, cook in batches. Roll them around so they crisp evenly on all sides. Once golden, transfer the rolls to a wire rack.
In a food processor or mini chopper, mix the mayonnaise, dry Ranch mix, milk, and avocado. Blend until smooth.
Serve the egg rolls with the dipping sauce.