In a small saucepan, heat ½ cup plus 1 teaspoon (125 grams) cream and ½ tablespoon (6 grams) sugar over medium heat.
In a medium bowl, whisk together egg yolks and remaining ½ tablespoon (6 grams) sugar. Whisking constantly, slowly pour hot cream mixture into yolk mixture. Return cream mixture to saucepan, and cook until a candy thermometer registers 180°F (82°C).
Place chocolate in a medium bowl. Strain hot cream mixture over chocolate, and let stand for 5 minutes. Whisk until ganache is smooth and shiny.
In the bowl of a stand mixer fitted with the whisk attachment, beat remaining 1 cup plus 3 teaspoons (255 grams) cream at high speed until soft peaks form. Fold whipped cream into ganache until combined.
Recipe by Bake from Scratch at https://bakefromscratch.com/french-silk-pie/