With an ice cream scoop, form 4 large balls of ice cream. Place on a waxed paper lined sheet and cover with plastic wrap. Freeze for at least 2 hours.
In a bowl, combine the cornflake crumbs with either the coconut, walnuts or cookie crumbs (or any combination). Spread the mixture in a shallow dish.
Dip the ice cream balls in the crumb mixture and freeze for 30 minutes.
In a bowl, beat the eggs and sugar. Dip the coated ice cream balls into the eggs, then roll in the crumb mixture, coating completely. Freeze for 1 hour. (If necessary, or for a thicker crust, roll again in eggs and crumbs until the balls are completely coated.)
Heat the oil in a large pot or fryer to 400 degrees F. One at a time, lower the balls into the oil and fry until golden brown, about 30 seconds to 1 minute. Remove from the oil and place in a dessert bowl. Drizzle with chocolate sauce and whipped cream, as desired. Repeat with the remaining ice cream.