In a medium-sized, heatproof bowl, whish egg yolks until blended and set aside. In a medium sauce pan, bring cream to a gentle boil over medium low heat. Remove from heat and stir in chopped chocolate, stirring until chocolate is completely melted and mixed inches Whisk chocolate mixture in a thin stream into egg yolks. When chocolate is thoroughly incorporated, return mixture to saucepan over medium-low heat. Stir mixture constantly with a wooden spoon until thickened to a smooth, pudding-like consistency (about 5-10 minutes). Do not allow mixture to boil. Remove pudding mixture from heat and sift in malt powder, whisking until thoroughly dissolved. Stir in vanilla extract. Strain pudding mixture in to a clean, dry heat-proof bowl and allow cooling for 10 minutes. Whisk mixture to combine any skin that might have formed on top of the pudding during cooling. Fill pie shell and refrigerate for 3 hours or up to 1 day before serving.