Heat oven to 450°F. Grease bottom and side of six 6-oz custard cups with shortening. in 2qt saucepan, melt chocolate and butter over low heat, stirring frequently. Cool slightly.

Meanwhile, in a large bowl, beat eggs and yolk with wire whisk or hand beater until well blended. Beat in powdered sugar. Beat in melted chocolate mixture and flour. Divide batter evenly among custard cups.

Bake 11-13 minutes or until sides are set and cake feels soft when touched in center. Run small knife or spatula along sides of cakes to loosen. Immediately turn upside down onto individual plates; remove cups. Sprinkle with additional powdered sugar. Top with pie filling. Serve warm.