In a saucepan, whisk the eggs and granulated sugar together.
Put the saucepan over low heat and cook mixture until it reaches 160°F. Check the temperature often and do not overcook.
Using a glass bowl, melt the chocolate in the microwave. Do not keep it in there too long or it will burn. You may also melt it on the stove using a double water boiler, but the microwave is just so much easier.
Mix together the melted chocolate, vanilla, and egg/sugar mixture until smooth. Let this cool until it is just warm, but don't let the chocolate harden. Stir Occasionally.
Beat the butter in the stand mixer for a few minutes, until it is fluffy. Afterwards, add in the chocolate mixture and mix on high for about 5 minutes. Transfer this into a separate bowl so you can continue to use your stand mixer.
With the stand mixer bowl now clean, beat the cream on high until it begins to thicken. Add in the powdered sugar and then continue to beat until it forms stiff peaks.
Fold the cream into the chocolate mixture to combine.
Pour the mixture onto the pie crust and spread evenly throughout the bottom and sides. Place into fridge.