Do Ahead: Individually separate the oreo cookies and scrape off the cream. Set them in a food processor to grind until they are fine crumbs.
Spread the sugar on a small baking sheet. Set it in the oven and set the oven to preheat the oven to 225 F. The sugar just needs to warm until the oven is preheated, about 8-10 minutes.
While the oven is preheating, set the egg whites in the bowl of a stand mixer. Affix the whisk and start the mixer on low speed. As it starts to bubble, add the cream of tartar. Whisk until the egg whites are foamy all over, even at the bottom of the bowl.
Once you have a fully frothy mix, add the hot sugar one spoonful at a time, waiting about 10 seconds before adding another. Once all the sugar is in, gradually increase the mixer speed until you are on medium high. Whip it until you have stiff peaks - this can take up to 10 minutes. Toward the end of whisking, add the salt and vanilla.
Once you have stiff peaks (check the the meringue that's at bottom of the bowl to be sure it's all stiff), sprinkle in the cookie crumbs and use a rubber spatula to gently fold them in.
Prepare a cookie sheet with parchment paper. Use a disher to portion the meringue into heaped 3 tablespoons of meringue per cookie onto the pan. If you plan to put the whipped cream on top you have the option to indent them slightly on top with the back of a spoon. You’ll have around 10-12 meringues.
Bake in the center of the oven for 1 hour and 20 minutes (still at 225 F). They are done when you can carefully lift them from the pan and they come off clean, without sticking to the parchment. Turn off the oven and leave them there overnight (or at least for a few hours). Store them in an airtight container.
For the Raspberry Whipped Cream: Beat or whisk together the heavy whipping cream, vanilla and sugar either with a hand mixer or using a whisk until you have soft peaks. Fold the raspberries into the whipped cream.
Serve the meringues topped with the whipped cream.