To make the raspberry sauce, heat raspberries and 1/2 cup of water in a pot over medium heat and bring to a gentle boil. When the raspberries are mushy, mash the raspberries with the back of the spatula into little pieces and let boil for about 8 minutes, until the water becomes red in color and absorbs enough flavours from the raspberries.
Prepare the cornstarch slurry by mixing 1 tsp of cornstarch and 2 tsp of water in a small bowl and set aside.
Remove the raspberry water mixture from heat and pass through a mesh strainer. Discard the raspberry lumps and transfer the strained juice back into the pot and heat over medium heat. Add the honey and vanilla extract and mix well. Once the mixture comes to a boil, add the cornstarch slurry while continuously stirring the sauce. Continue stirring until sauce comes to a boil and becomes thicker. Remove from heat and let cool to room temperature.