Melt 1 tablespoon of the butter in 2-quart saucepan on medium heat. Add shallots; sauté 5 minutes or until softened. Add wine, vinegar, vanilla, red pepper and salt. Bring to boil. Reduce heat to low; simmer about 15 minutes or until liquid is reduced by half.
Gradually whisk in remaining cold butter, 1 tablespoon at a time. The butter must melt gradually to form a creamy sauce. If necessary, move pan off the heat to keep it from getting too hot. Continue whisking in the butter until well blended. If desired, strain through a fine sieve. Keep warm until ready to serve