Puree the raspberries in a food processor or smash with a potato masher. Transfer them to a bowl or measuring pitcher with a pouring spout and add the simple syrup. Stir well and taste; significant seasonal variation in raspberries means the sweetness of your mixture may need tweaking. Add the cream and stir very, very minimally. The swirl effect in the finished pop is an aesthetic (and gustatory) effect really worth trying to achieve, and the act of pouring the cream into the molds will do a lot to homogenize the mixture, so don't overmix it. Pour the mixture into your ice pop molds, leaving a little bit of room at the top for the mixture to expand. Insert sticks and freeze until solid, 4 to 5 hours. Unmold and transfer to plastic bags for storage or serve at once.
Combine the sugar and water in a small saucepan and bring to a simmer over medium-high heat, stirring until the sugar dissolves and the mixture is transparent. Turn off the heat and let cool. Add any spices before the mixture starts to simmer; add any herbs only after you've turned off the heat. Store plain and infused syrups in sealed containers in the fridge.
Reprinted with permission from People's Pops by Nathalie Jordi, David Carrell, and Joel Horowitz, copyright (c) 2012. Published by Ten Speed Press, an imprint of the Crown Publishing Group.