1/2 oz Aperol
1/2 oz orange juice
Prosecco
thin orange slices (for garnish)

In lowballs with ice, add Aperol and orange juice, stir together, top with prosecco, garnish with a slice of orange

Via Bon Appetit: http://www.bonappetit.com/recipes/cookingclub/2009/03/orange_ape...

"This Italian spin on the Mimosa gets its unique flavor from Aperol, a bright-orange Italian liqueur made from bitter oranges, rhubarb, and herbs. It's similar to Campari, but less bitter and more floral. In Italy, Aperol is served on the rocks mixed with Prosecco and a splash of club soda. In this recipe, the club soda has been replaced with a little fresh orange juice."