Make the filling. In a medium bowl, sprinkle the lemon juice over the apple slices. Combine the cinnamon, nutmeg, tapioca pearls, cornstarch and salt together with the sugar. Gently toss the apple slices and raspberries with the sugar mixture. Put the apple mixture into crust-lined pie plate and mound it slightly in the center. Sprinkle the amaretto evenly over the filling. Distribute the remaining 2 tablespoons butter chunks over the top. Brush the top edges of the dough with egg white.