The Mazatlan (Tequila Manhattan)

½ oz Paula’s Texas Orange
1½ oz añejo tequila
1 oz sweet vermouth
a dash Angostura bitters
an orange peel for garnish

Stir with ice (don’t shake) and serve up or in an old fashion glass. Optionally garnish with an orange twist.

Similar
Paula’s Perfect Margarita (+lime juice; -sweet vermouth, bitters), Ginger Margarita (+syrup; -sweet vermouth, bitters), Paula’s Margarita (+lime juice; -sweet vermouth, bitters), Agavoni (+Campari; -citrus liqueur), Mexican Standoff (+coffee liqueur; -citrus liqueur, sweet vermouth)
Source
http://pts.nwalsh.com/recipes/martinistyle/mazatlan.html