Prepare the Filling
In a large mixing bowl, combine the crab meat, cream cheese, green onions, soy sauce, garlic powder, ginger (if using), and lemon juice (if using). Stir well until the mixture is smooth and the ingredients are evenly distributed.
Assemble the Egg Rolls
Lay one egg roll wrapper on a clean, flat surface, with one corner pointing toward you (like a diamond shape).
Spoon about 2 tablespoons of the crab and cream cheese mixture into the center of the wrapper.
Fold the bottom corner of the wrapper over the filling, then fold in the sides. Roll up the wrapper tightly, sealing the top corner with a small amount of water. Repeat with the remaining wrappers and filling.
Heat the Oil
Heat about 2 inches of oil in a frying pan or deep fryer over medium-high heat. The oil should reach around 350°F (175°C).
Fry the Egg Rolls
Carefully place the egg rolls into the hot oil, a few at a time, being careful not to overcrowd the pan. Fry for 3-4 minutes, or until the egg rolls are golden brown and crispy.
Use tongs to turn the egg rolls halfway through frying to ensure they cook evenly.
Drain and Serve
Remove the egg rolls from the oil and place them on paper towels to drain excess oil. Let them cool slightly before serving.