Add all ingredients to a medium saucepan or saute pan, and stir to combine. Cover the pan and let macerate for 2 hours, stirring once after 1 hour. The berries will look glossy and there will be accumulated juices in the pan.

Uncover the pan and set it over medium heat, and bring to a low boil. Then reduce the heat to medium-low and let the mixture simmer. Stir occasionally, until the raspberries cook down into a sauce. This will take about 7 to 10 minutes, depending on the firmness of the berries. If you are using especially firm berries, go ahead and smoosh them up.

Remove pan from heat. Enjoy right away or let it cool a bit. Or transfer to jars with lids, let cool to room temperature, and store in the fridge to consume within 5 days. To freeze, transfer raspberry sauce to jars, leaving a 1/2" of headroom for expansion during freezing. Wipe the rims clean and top with a lid. Let cool completely before storing in the freezer.