In a medium-sized saucepan over low heat, add eggs and sugar. Whisk until combined. Continue to whisk until mixture reaches 160°F on an instant-read thermometer.
Once the egg mixture reaches 160°F remove from heat and add chocolate chips, salt, and vanilla. Mix until combined. Allow to sit at room temperature while you work on other portions.
In a mixing bowl, add butter and whisk until creamy. Pour in chocolate/egg mixture and beat until combined with butter.
In a separate mixing bowl, whisk heavy cream, until it begins to get stiff. Once you see stiff peaks begin to form, add powdered sugar and vanilla. Whisk until stiff.
Remove half of the whipped cream and set aside. Pour the chocolate mixture into the remaining whipped cream, and whisk until combined.
In a microwave-safe bowl, combine ¼ cup chocolate chips and 2 tablespoons heavy cream. Microwave for thirty seconds and then stir. Pour over the crust and refrigerate until set.
Remove from fridge and pour chocolate filling into the crust. Place back in the fridge to store.