Seville Orange and Cava Cocktail

Cut 4 twists from the oranges (with knife or zester). Juice the oranges into a measuring jug (avoid seeds). Add sugar to juice and mix until completely dissolved. Chill 4 champagne glasses and divide juice mixture between each. Add a splash of Aperol to each glass then top up with cava. Garnish with an orange twist. Sit back and sip!