Put the Cake Base on a Serving Platter (You can bake one, or just use the pre-baked one)
Strain the cans of mandarins (save the liquid) pick out 12-16 "pretty" mandarin slices and and set them aside to use for decoration.
Get out a larger bowl with a lid that seals tight. (I used a rectangular storage container with a lid) Put in the rest of the mandarins, all the mandarin liquid from the cans, the heavy cream, the Sahnesteif, and the Paradise Cream.
Put on the lid (make sure it's really ON tight)
Shake it.... for 1-2 minutes.
Open, maybe give it a stir to make sure everything came off the bottom
Seal and shake one more minute.
Let it sit for a minute (it will stiffen up as it sits)
Spoon the mixture into the cake base.
You will be able to mound it because it gets stiffer (it's like magic)
Decorate with the reserved mandarin slices (back to back, they look like butterflies)
Sprinkle with chopped pistachios or grated chocolate.
Refrigerate for an hour
Cut and serve.
