This recipe is modified from http://www.pearpanache.com/cocktails/the-peppered-poire/ :

2 oz Poire William or similar pear-flavored liqueur
1/2 ounce black pepper simple syrup (recipe follows)
Sparkling wine

To make The Peppered Poire, add the gin, Poire William, pear puree and simple syrup to a cocktail shaker. Add ice and shake well. Strain the contents into a champagne flute and top off the glass with sparkling wine. Float 2 or 3 whole black peppercorns on top of the fizz, if desired.

For the syrup: See the black pepper modifications of the simple syrup recipe.