3⁄4 oz Bourbon
7 ds Peychaud's Bitters
4 oz Champagne
1 twst Orange peel (as garnish)
Stir first 4 ingredients with ice, strain into flute, top with chilled Champagne, stir gently, garnish.
Some recipes call for 1 oz Bourbon
See the NYT article in the comments.
Adam Seger, Seelbach Hotel, Louisville, KY
The Joy of Mixology, Gary Regan
Champagne, Bourbon, Triple sec, Peychaud's Bitters, Bitters, Orange peel