Juice about 4-5 fresh lemons to yield 1 cup of lemon juice. In a blender, combine lemon juice, 1 cup of granulated sugar, and 1 cup of cold water. Add 1 cup of fresh raspberries and blend on high for about 30 seconds.

Using a fine mesh sieve, strain the blended mixture over a pitcher. Press down gently to extract as much liquid as possible for a smooth lemonade base.

Add the remaining 3 cups of cold water to the pitcher and stir well until fully combined. Adjust the sugar if needed.

In a chilled mixing bowl, combine 1 cup of heavy whipping cream and 1 teaspoon of vanilla extract. Whip on medium speed for about 2–3 minutes until soft peaks form.

Gently fold in 1 cup of the lemonade mixture into the whipped cream until it becomes a pastel pink.

To serve, fill each glass with ice cubes and pour the pink lemonade over it. Top with the whipped cream and garnish with raspberries and lemon slices if desired.