Make the crusts first. In a food processor with the "S" blade, process the dates until mush.
Add the coconut, coconut oil, agave, and salt and process until it begins to clump.
Last, add the walnuts and process until the walnuts are fully incorporated and the mixture sticks together.
Divide the crust mixture evenly into and press into the bottom and sides of eight paper-lined cupcake cups. Put in the freezer for about a half hour, until firm.
For the filling, in the food processor with the "S" blade, process the avocados, bananas, lime juice and zest, and agave. It takes a minute or two, but this will become velvety smooth and the consistency of thick pudding.
Spoon the filling into the tart crusts and chill well before serving.