In a mixing bowl, combine the softened cream cheese, shredded cheddar cheese, diced jalapeños, garlic powder, onion powder, salt, and black pepper. Mix until well combined.
Lay an egg roll wrapper on a clean surface with one corner pointing towards you. Place about 2 tablespoons of the cheese mixture in the center of the wrapper.
Fold the bottom corner over the filling, then fold in the sides, and roll tightly towards the top corner. Brush the top corner with beaten egg to seal. Repeat with remaining wrappers and filling.
In a large skillet, heat about 2 inches of vegetable oil over medium heat until hot (about 350°F).
Carefully add a few egg rolls to the hot oil, frying in batches to avoid overcrowding. Fry for 3-4 minutes per side, or until golden brown and crispy.
Remove the egg rolls from the oil and place them on a paper towel-lined plate to drain excess oil.
Serve warm with your favorite dipping sauce, such as ranch or salsa.