Step 1

Whisk together first 6 ingredients in a 3-quart saucepan until smooth. Bring to a boil over medium heat, whisking constantly; boil 1 minute or until thickened. Remove from heat.

Step 2

Whisk in pecans, butter, and vanilla. Place a sheet of wax paper directly on surface of mixture to prevent a film from forming; chill 4 hours.