If you want a fuller caramel flavor, use the 3/4 cup (150g) of sugar to caramelize in step 2. The caramel flavor will be a bit more pronounced than the coffee flavor but I tried it both ways and like it, for different reasons. And you can use lowfat milk rather than whole milk, although it'll be less-smooth, but I wouldn't call this an overly rich dessert. It goes without saying that the stronger the espresso, the more forceful the coffee flavor will be. I tried it with a few long (allongé or lungo) shots of espresso as well as espresso made in a moka pot, and both were good. If you don't have an espresso maker, use good-quality instant espresso powder dissolved in hot water. Taste and make sure it's quite strong as it'll be diluted later with the other ingredients. I've mentioned some coffee alternatives in the post.I've not had experience using agar-agar, but fish-based gelatin is available and is said to work the same as standard gelatin. For more on gelatin, including using sheet gelatin, check my post on how to use gelatin. If you do try sheet gelatin, or another type, feel free to share how they work out in the comments.When done, because these aren't baked, you can simply pour the finished mixture into coffee or espresso cups or other decorative glasses. The number of servings will depend on how large or small you make them. The recipe plug-in I use to write up recipes so they're printable doesn't allow me to add a range of serving sizes (which I learned when they kept disappearing after I added them...) but this recipe will make 4 to 6 servings.