Peel apples. Dice into small pieces.
Heat butter in saucepan over medium heat.
Add diced apples to melted butter.
Stir in brown sugar and cinnamon.
Cook apples until tender, about 5 minutes.
Mix cornstarch with 2 tablespoons water.
Add cornstarch mixture to apples.
Cook until mixture thickens, then cool completely.
Place egg roll wrapper on clean surface.
Add 2 tablespoons apple filling to center.
Brush edges with beaten egg.
Roll tightly, sealing edges completely.
Heat oil to 350°F in deep fryer.
Fry rolls until golden brown, 2-3 minutes.
Remove and drain on paper towels.
Dust with powdered sugar before serving.