2 tablespoons white sugar
2 fresh lemon wedges
1 1/4 fluid ounces hazelnut liqueur (such as Frangelico®)
1 1/4 fluid ounces lemon-flavored vodka (such as Absolut Citron®)
Pour sugar onto a small plate. Cut a slit in the middle of each lemon wedge, slide around the rim of 2 shot glasses and dip rims into the sugar.
Fill a cocktail shaker with ice. Add the hazelnut liqueur and lemon-flavored vodka to the shaker. Cover and shake until chilled; pour into shot glasses. Hang the lemon wedges on the rims.