Preheat your oven to 350°F (175°C). Grease a 9-inch pie dish lightly.

Melt the butter and unsweetened chocolate in a medium saucepan over low heat, stirring until smooth. Remove from heat and let it cool slightly.

Stir the sugar into the melted chocolate mixture until combined. Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

Fold in the flour and a pinch of salt until just combined. Avoid overmixing to keep the pie tender.

Pour the batter into the greased pie dish, spreading it evenly.

Bake for 25–30 minutes or until the center is just set. The pie should have a slightly gooey texture.

Allow the pie to cool for 5–10 minutes before serving.