1. In a mixing bowl, combine the cream cheese, sugar, and vanilla extract until smooth and creamy. This was always my favorite part, watching simple ingredients transform into something magical.
2. In a small saucepan over medium heat, combine blueberries, lemon juice, and cornstarch. Cook until the mixture begins to thicken, about 5 minutes. Stir occasionally to prevent sticking.
3. Lay an egg roll wrapper on a clean surface, positioning it like a diamond. Add about 2 tablespoons of the cream cheese mixture and 2 tablespoons of the blueberry mixture onto the center of the wrapper.
4. Fold the bottom corner over the filling, then fold in the sides. Roll the wrapper tightly towards the top corner, sealing the edge with a dab of water.
5. Heat about 2 inches of vegetable oil in a frying pan over medium-high heat. Once hot, fry the rolls until golden brown, approximately 3-4 minutes per side. Be sure to turn them gently to achieve an even color.
6. Remove the egg rolls and let them drain on paper towels. Dust with powdered sugar before serving, if desired.

Remember to keep an eye on the egg rolls while frying, as they can brown quickly. This was a lesson I learned the hard way during a particularly lively cooking session with Mum!