Fill a large wine glass with ice.

Pour the limoncello and homemade raspberry syrup over the ice and stir gently to combine.

Top the mixture with the Prosecco and club soda.

Stir once more from the bottom up to mix without losing the carbonation, then garnish with fresh raspberries and a lemon wheel.

Combine the raspberries, sugar, and water in a small saucepan.

Bring the mixture to a gentle boil over medium heat, stirring until the sugar dissolves. Reduce heat and simmer for 5 to 7 minutes until the raspberries break down.

Crush the berries with the back of a spoon to release their juices, then pour the mixture through a fine-mesh strainer into a jar, pressing the solids to extract the liquid.

Let the syrup cool completely before use.