Place the raspberries, sugar, and water in a small saucepan over medium heat, stirring to combine and lightly break up the berries.
Bring the mixture to a gentle rolling boil and cook, stirring occasionally, until the liquid thickens slightly, about 5 minutes.
Remove the saucepan from the heat and pour the raspberry mixture into a bowl set with a fine-mesh sieve.
Use the back of a spoon to press the berries and juice through the sieve, leaving most of the seeds behind.
Taste the puree and adjust sweetness if needed. For extra brightness, add a small squeeze of lemon juice.
The puree is now ready to be poured over any dessert.
