01 - In a small bowl, whisk together lemon juice and granulated sugar until the sugar is completely dissolved. Stir in cold water.
02 - In a separate bowl, use a hand mixer or whisk to beat heavy whipping cream until soft peaks form, approximately 1 to 2 minutes. Add sweetened condensed milk and continue whipping until mixture is thickened and smooth.
03 - Divide ice cubes evenly between two glasses. Pour the prepared lemon mixture into each glass.
04 - Spoon or pipe the whipped cream mixture on top of each glass, distributing evenly.
05 - Gently stir each drink just before enjoying. Garnish with lemon slices if desired.