Step 1

Place a fine-mesh sieve over a medium heatproof bowl and set aside. In a medium saucepan, combine dark-brown sugar, cornstarch, and salt. In a medium bowl, whisk together milk, cream, and egg yolks; add to saucepan.

Step 2

Whisking constantly, cook over medium-high until mixture thickens and is bubbling, 8 to 12 minutes. Reduce heat to medium-low and cook, whisking, 1 minute.

Step 3

Remove pan from heat and pour mixture through sieve into bowl. Stir in butter and vanilla until combined.

Step 4

Press plastic wrap directly against surface of pudding to prevent skin from forming and refrigerate 3 hours (or up to 3 days). To serve, whisk until smooth and divide among four small bowls.