In a medium bowl, pour the boiling water over the raspberry jello and stir with a spoon until dissolved. Add frozen raspberries and lemon juice and mix well. Refrigerate the mixture until it starts to thicken (1-2 hours) - you don't want it completely set up, just thicken like spreadable pudding. If you want to speed up this process, stir the jello mixture over a bowl of ice water to cool faster.
In a blender or in a bowl with a handheld or stand mixer, whip the cream cheese, powdered sugar, and sour cream until smooth. Add the vanilla and whipping cream and whip until thick and creamy.
In a glass bowl or dish, layer the raspberry jello mixture and cream, two or three layers of each, depending on the size of the dish. I use an 8-inch bowl and the three layers of each are rather thin, it doesn't have to be perfect.
Cover and chill the salad for 2-3 hours until set.
Notes
Raspberry Mixture: it's really important to let the raspberry mixture start to set up before layering or else the layers will blend together instead of being separate.Layer Thickness: the layers are on the thin side (and you won't need an overly large bowl or dish) - if you want thicker layers, double the recipe.