1 sugar cube
1/4 teaspoon absinthe (or a substitute, such as Pernod®)
5 fluid ounces sparkling wine
1/2 teaspoon cognac, or to taste
1 lemon twist
Place sugar cube into a Champagne glass. Drip absinthe over the cube. Fill glass with sparkling wine. Float cognac on top; garnish with lemon twist.