Place chopped chocolate in a medium heatproof bowl. Set aside.
In another heatproof bowl or glass measuring cup, warm the cream in the microwave until nearly boiling.
Remove 2 tablespoons of the hot cream, pouring it into a small bowl. Dissolve the espresso powder (see note) in the cream.
Pour both the espresso mixture and the rest of the hot cream over the chopped chocolate. Stir until all chocolate has melted and the mixture is smooth. (If the chocolate doesn't melt completely, you can place it in the microwave for 15-second intervals until smooth).
Add chocolate extract (see note) and stir to combine. Allow truffle filling to set at least 4 hours in the refrigerator, or overnight at room temperature.
Once the truffle filling has set, scoop out truffles, about 1.5" each (see note). Place truffles on a baking sheet and refrigerate for at least an hour.
Once chilled, place one hazelnut on top of each truffle (see note). Dust hands with cocoa powder (to keep the truffles from sticking) and roll each truffle into a ball, pushing the hazelnut into the center of the filling as you roll. Return to the refrigerator.
For Truffle Coating:
Line a baking sheet with parchment paper and set aside.
In a small heatproof bowl, combine the chopped chocolate and vegetable shortening. Microwave on 30 second intervals, stirring after each interval, until melted and smooth.
Dip each truffle in melted chocolate, coating each completely, then set on the prepared baking sheet. Top with a drizzle of chocolate and chopped hazelnuts, if desired.
Allow chocolate to set either at room temperature or in the refrigerator. Enjoy!
Notes
Note on espresso powder: I’ve found it difficult to find espresso powder, especially one that’s fine in texture and isn’t already as hard as a rock. I use King Arthur Baking’s brand, as it’s very fine and made specifically for baked goods.Note on chocolate extract: Chocolate extract lends amazing flavor to anything chocolate! You can find it online, or even better, make yourself some Homemade Chocolate Extract for next time!Note on hazelnuts: I placed one whole hazelnut in the center of each truffle, because I wanted the outsides of the truffles to be smooth. For more texture, you can mix chopped hazelnuts right into the filling before you chill it.Note on scooping truffles: I use a small cookie scoop to portion out my truffles. A scoop isn't a necessity, but the process is much cleaner and you end up with truffles that are uniform in size.