Place the fresh cranberries in a small pitcher or bowl and add the sugar or simple syrup. Use a muddler or the back of a spoon to gently crush the berries, releasing their juice and creating a vibrant red mash. You should hear a slight squish and see the berries break apart.
Fill each serving glass with about 2 ounces of the cranberry mash, allowing the bright red color and juicy bits to settle at the bottom. Gently tap the glass to level the mixture.
Pour the chilled sparkling wine slowly into each glass, tilting slightly to preserve the bubbles. Gently pour until the glass is nearly full, listening for the lively fizz as the bubbles lift the fruit mash upward.
If desired, add a splash of orange liqueur to deepen the citrus flavor and add a touch of sweetness. Stir gently with a spoon or stirrer to combine everything without losing too much fizz.
Garnish each glass with a few fresh cranberries and a sprig of mint or thyme for a festive, aromatic touch. A thin slice of orange can also add a citrusy pop and visual appeal.
Serve immediately to enjoy the lively bubbles, bright tartness, and beautiful ruby hue. Cheers to a playful, festive brunch drink!