01 - Combine sugar and water in a small saucepan. Heat over medium heat, stirring constantly until sugar completely dissolves. Remove from heat and allow to cool to room temperature.
02 - Puree raspberries in blender or food processor until completely smooth. For seedless sorbet, press puree through fine-mesh sieve into clean bowl, discarding seeds.
03 - Whisk lemon juice and cooled simple syrup into raspberry puree until thoroughly incorporated. Stir in lemon zest if using.
04 - Pour mixture into ice cream maker and churn following manufacturer's instructions until mixture reaches thick, slushy consistency, approximately 20-25 minutes.
05 - Without ice cream maker: Transfer mixture to shallow freezer-safe container. Freeze 1 hour, then rake with fork to break ice crystals. Repeat every 30 minutes for 2-3 hours until smooth and scoopable.
06 - Move sorbet to airtight container and freeze minimum 2 hours before serving. Scoop into bowls or cones and garnish with fresh raspberries and mint if desired.