Late to the orange party, but when I have an orange to lend to a cocktail, I almost ALWAYS turn to the as-yet-unnamed tequila variation of a Monkey Gland that Phil Ward opened my mind to many years ago at Death&Co.
2 oz blanco tequila (or reposado, why not)
1 oz orange juice
1/2 oz grenadine (homemade unless you have some really good bottled stuff)
dash absinthe