Peel jicama. Grate into fine strips using a box grater. Do the same for carrots.
Combine ground pork, soy sauce, and ground pepper in a bowl. Mix well.
In a wok or large pan, heat vegetable oil. Add seasoned ground pork. Cook for 3 minutes. Add onions and garlic. Cook for another 2 minutes.
Add grated jicama, carrots, and cabbage. Stir to get everything well mixed.
Add salt and pepper and continue to cook for about 5 minutes. Turn off stove and stir in sliced green onions.
Place a metal colander on a shallow bowl. Transfer cooked filling to metal colander to drain off excess sauce. Allow filling to cool.
Place a sheet of spring roll wrapper on a clean work surface with one of the pointed ends towards you. Place 2 to 3 tablespoons of filling on the wrapper.
Fold the pointed end over the filling. Then fold in both the right and left sides of the wrapper.
Moisten the remaining edges of the wrapper with a little water. Roll and seal. Place spring rolls on a plate in a single layer. Repeat with remaining wrappers and filling.
Preheat oven to 425˚F (220˚C).
Spray spring rolls on the plate with cooking spray. Transfer spring rolls onto a wire rack over a baking tray with sprayed side down. Again, spray the spring rolls with cooking spray.
Bake spring rolls for 25 to 30 minutes. Remove and serve immediately.