1. Preheat oven to 350°F (175°C). Grease and line an 8-inch round cake pan.

2. In a heatproof bowl, melt chocolate and butter over a saucepan of simmering water (double boiler), stirring until smooth.

3. Remove from heat and stir in sugar, salt, and vanilla.

4. Beat in eggs one at a time, then fold in flour until just combined.

5. Pour batter into the prepared pan and bake for 25–30 minutes, until the center is just set.

6. Cool completely in pan before removing.

7.

8. To make the crème anglaise: In a saucepan, heat milk, cream, and vanilla bean until just simmering. Remove from heat.

9. In a bowl, whisk egg yolks and sugar until pale.

10. Gradually whisk hot milk into yolks, then return to saucepan.

11. Cook over low heat, stirring constantly, until mixture thickens and coats the back of a spoon (do not boil).

12. Strain into a bowl and chill until ready to serve.

13. Serve slices of gâteau with a drizzle of crème anglaise.