Fill a stemmed wine glass three-quarters full with ice cubes, until the glass feels cold against your hand.

Pour 1.5 oz orange aperitif liqueur over the ice, letting the color settle at the bottom of the glass.

Add 3 oz chilled prosecco slowly, tilting the glass slightly so the foam does not rise past the rim.

Top with 2 oz chilled club soda and stir once with a bar spoon, just enough to lift the orange color through the whole glass without flattening the bubbles.

Tuck a thin orange wheel against the inside of the glass and serve right away, while the glass is still sweating on the outside.