Don't be tempted to substitute a pudding mix here. The delicate flavor is well worth a bit of effort.
Whisk together first 4 ingredients in a heavy 3-qt. saucepan. Cook over medium-heat, whisking constantly, 10 to 12 minutes or until thickened. Remove from heat; stir in vanilla bean paste. Cover and chill 3 hours.
*2 tsp. vanilla extract may be substituted.