Here's what I did:
First I bought two of these, which I got for a total of $2 at Bed Bath and Beyond.
Then I melted maybe 6 oz. of bittersweet chocolate in a bowl over simmering water. When it was melted I used a pastry brush to paint a moderately thick layer of chocolate all over the inside of each mold.
Into the freezer!
While those set up, I made the filling:
1-1/2 Tbsp. Earth Balance
1/2 tsp. vanilla (coconut flavor would be a good sub)
1 Tbsp. soy milk (or any milk sub)
about 1 cup powdered sugar (Hain organic powdered sugar is vegan)
about 3/4 cup sweetened flaked coconut
Nuke the margarine, vanilla, and soy milk together until the margarine is melted and everything is very hot. Stir well, then stir in as much powdered sugar as it takes to get something stiff but still fluid. Stir in as much coconut as it can hold while still being sticky and holding together well.
By this time, the chocolate should be set. Scoop half-teaspoonsful or so of filling into each mold, pressing it in to minimize air pockets. It should come to right near the top but not even with it, and the flatter you can get the tops, the better.
Then brush more chocolate over the tops, shaking the tray a little to help it settle into any cracks. Try to clean the sloppiness away from the edges before you refreeze them since you'll want to handle them as little as possible when they're done to minimize melting (you can see that I didn't think to do this).
Back to the freezer! When they're nice and firm, push them out of the molds. I had to be quite aggressive with some of mine, but only one cracked even a little bit.
This made about 20 in my molds (I ran out of filling, so I tried cutting some leftover melted chocolate with Kalhua to fill the rest; we'll see how that works out).
Keep chilled as long as possible before serving/giving.
Loch Lomond - When We Were Mountains - The Mountain