Bring first 3 ingredients to a boil in a 2-qt. saucepan over medium heat, whisking constantly; boil 1 minute. Remove from heat; whisk in powdered sugar and vanilla until smooth. Stir gently 3 to 5 minutes or until mixture begins to cool and thickens slightly. Use immediately.
Very yummy, but to look like the icing on the picture of the bundt cake, I recommend adding more powder sugar to stiffen this up a bit. Another reviewer said the same on her comment of the cake.