In a heat proof bowl or the top of a double boiler, whisk together the sugar and eggs. Place over a pot of simmering water (creating a double boiler) making sure that the bottom of the bowl does not touch the water. Whisk constantly until the mixture reach 160 degrees.

Remove the sugar/egg mixture from the heat and stir in the melted chocolate and vanilla. Set aside to cool for 10 minutes, stiring occasionally.

While the chocolate/egg mixture cools cream the butter. In the bowl of a stand mixer fitted with a paddle attachment, cream the butter until light and fluffy.

With the mixer on low speed, slowly pour in the chocolate/egg mixture. Increase the speed to medium-high and beat for 5 minutes until light and fluffy. Set aside.

In a clean bowl, beat the heavy cream and powdered sugar until stiff peaks form. Divide the whipped cream in half and fold half the whipped cream into the chocolate mixture until fully combined. Pour filling into baked pie crust and chill in the frig for at least 4 hours. Refrigerate the other half of the whipped cream. It will be used to top the pie.

After the pie has chilled, top with the cherry pie filling.

Fit a pipig bag with a large star tip and fill with the reserved whipped cream. Pipe the whipped cream around the edge of the pie. If you wish you can garnish the pie with shaved chocolate or drizzle with melted chocolate.

Serve immediately or refrigerate until you are ready to serve.