Combine sugar and water in a saucepan over medium-high heat to create a simple syrup. Simmer, stirring occasionally, for about 30 minutes or until all the sugar has dissolved.
Combine raspberries and lemon juice in a food processor and blend until smooth. Strain out raspberry seeds in a fine mesh strainer and discard.
Mix together simple syrup and blended raspberry and lemon juice mixture until combined. Transfer to an 8x8” baking dish, cover, and freeze for about 10-12 hours.
Notes
You can use bottled lemon juice instead of fresh, if desired. One lemon yields about two tablespoons of lemon juice.
You can also use frozen raspberries instead of fresh, if desired. Allow to thaw before use.