Put the chocolate, espresso powder, vanilla, cardamom, and sea salt in a heatproof bowl.Heat the almond milk and cream in a saucepan over medium heat until steam rises from the edges (or microwave for about 3 minutes). The milk needs to be quite hot or it won't melt the chocolate fully (if that happens, though, you can just microwave the whole mixture for a minute or so). Pour the hot milk into the bowl with the chocolate and cover with a plate or pot lid. Wait five minutes to give the chocolate time to melt.Whisk the mixture until smooth, and whisk in maple syrup to taste, keeping in mind that the sweetness comes through a little less once the fudgesicles are frozen.Divide between popsicle molds, insert sticks, and freeze until firm, about 6 hours.When you're ready to serve, run the molds under hot water briefly to loosen the popsicles.