In a large mixing bowl, combine the heavy cream, sweetened condensed milk, and vanilla extract. Using an electric mixer, whip the mixture on medium speed until soft peaks form, about 3-5 minutes.

Gently fold in the raspberry puree into the whipped cream mixture until well combined, creating a marbled effect.

In serving glasses, add a few ice cubes and pour in the lemonade until the glass is about three-quarters full.

Spoon the whipped raspberry cream mixture on top of the lemonade, filling the glass to the rim.

Garnish with lemon slices and fresh raspberries. Serve immediately with a straw or spoon.