2 oz lemon juice, freshly squeezed
2 ounces honey syrup (see notes)
Put raspberries into a bowl and using a spoon or muddler, muddle them until they are completely broken down.
Strain into cocktail shaker, removing all the seeds and solids.
Fill the cocktail shaker halfway with ice and add the remaining ingredients except the lemon garnish.
Shake until the container is ice cold; about 15-20 shakes.
Fill two Collins glasses with ice and pour the mixture into the glasses.
Top with chilled Prosecco and garnish with a lemon slice.