Smooth criminal chocolate mousse tarts

From: http://mynewroots.org/site/2010/04/smooth-criminal-chocolate-mousse-tarts-2/

(I failed at successfully keeping the tarts together so I normally just make the mousse)

Maple Walnut Crust
Ingredients:
1 ½ cups organic walnuts
2 Tbsp. maple syrup
a pinch fine sea salt

Chocolate Avocado Mousse
Ingredients:
4 ripe avocados
10 very soft dates (soaked if necessary)
4 Tbsp. raw agave nectar
2 Tbsp. high-quality raw cacao powder (or cocoa powder if you don’t have the other)

Directions:
1. Place walnuts in a food processor and pulse until chunky. Add the maple syrup and sea salt and pulse until the mixture is combined. (You can create a smoother crust by blending longer if you like, but in my experience leaving some chunks is a good idea to add contrast against the smooth chocolate pudding).
2. Get out a muffin pan. Scoop out a couple tablespoons of the walnut mixture at a time and press into the bottom of a muffin cup. Press firmly so that the walnut mixture is compact and holds together. You should be able to fill about 8 cups with the walnut crust. Refrigerate.
3. Finely chop the dates.
4. Cut open all the avocados and scoop them out into a clean food processor. Blend. Add the other ingredients and blend to incorporate.
5. Remove walnut crusts by running a knife around the perimeter to loosen, then lift out. If the crust breaks or becomes dented, simply press it back together once it’s out the mold.
6. Spoon a large dollop of avocado mouse on top of the crust base. Garnish with whatever fruit you have on hand (fresh berries, banana, dates, pomegranate, pineapple…). Serve to very lucky people.
Notes: You can change things up by making a whole tart – simply press the walnut mixture into a tart shell, spoon the avocado pudding on top and slice.
If you have any extra filling, just keep it in a sealed container in the fridge for up to 2 days and eat it like pudding. It’s great for breakfast!