Be sure that you’ve frozen a small handful of raspberries and blueberries. The raspberries will not break properly if they aren’t frozen, so this step is important.
Add all the ingredients for the crust into the blender. Blend on full speed until the mixture is crumbly and somewhat sticky. You may need to open the blender, spoon it around a little and blend again.
Spoon the mixture into a bowl and set it aside for now, then clean out the blender.
Remove the skin and pit from the avocado and add it to the blender, then add the rest of the filling ingredients in. Blend on full speed again until everything is completely smooth and well mixed. Again, use a spoon to mix it after a while, then put it back to be blended on high speed again.
Leave the avocado chocolate mousse in the blender for now.
Prepare 3 mini tartlet pans and three muffin parchment paper (believe me, you will find the parchment paper useful, as it helps get the crust OUT of the pans easily).
Put the muffin parchment paper on the tartlet pans.
Spoon ⅓ of the filling onto the muffin parchment paper sitting on the tartlet pan and press it around to form a crust. Then, add a couple of spoonfuls of avocado mousse in the middle and use a spoon to even out the top.
Finally, get a frozen raspberry or two and break it into small pieces and spread it on top of the tart. Add a blueberry as well.
Repeat for the other two tarts and eat any remaining avocado mousse filling.
put it in the freezer for about 20-30 minutes, then carefully take the tarts with the parchment paper out of the tartlet pan, and peel the parchment paper off. (If you didn’t use it, you may end up furiously scraping the crust off the pan, with little or no success, resulting in broken tarts.)