One of the nice things about silicone molds is that you can squeeze them to get the bubbles out of the chocolate and at the same time, coat the sides up to the rim. Once they've hardened, you can pipe in the filling, but make sure you leave some room so that you can seal the bottoms off with more chocolate. Give it a few taps to level it off, and fill in the rest of the mold.
Sweetened cocoa powder tends to get better reviews than the unsweetened kind, and you can see the larger grains of sugar that have settled on top of this one.
I played with a few different widths and ways of passing over them, but I think thin, narrowly spaced lines look the best. I'll probably skip the cocoa powder next time, and maybe dip them for a shiny coat before the drizzling. My friend Pete took me up on an offer to trade tasty things for pi and space invader molds so expect a pair of posts on those soon!
Next post: Truffles!