• Prepare hazelnut praline (recipe below), if using (recipe below) up to 2 days in advance, and set aside until ready to use.
• Chill a jar of Nutella in the fridge for at least 2 hours or overnight. Chilling is key, so that the Nutella maintains a round shape and doesn't spread out when scooped.
• Line a baking sheet with parchment paper or silicone mat. This will make the frozen Nutella balls peel easily from the baking sheet.
• Using a tablespoon size ice cream scoop or a melon baller, scoop out 15 rounded tablespoons of Nutella onto the prepared baking sheet. Freeze until solid, at least one hour or overnight. For a perfectly round shape, you might want to lightly roll the balls between cold hands after about 30 minutes of freezing.
• Keeping the Nutella balls in the freezer, microwave 6 ounces of the chocolate, stirring every 30 seconds until about two-thirds melted, about 1 to 2 minutes. Remove from microwave and add remaining 2 ounces of chocolate, and stir until melted. If necessary, zap it back in the microwave for no more than 5 seconds to complete the melting. Transfer melted chocolate in a deep bowl or large cup.
• Take the Nutella balls out of the freezer. Dip about 1/2 an inch of each lollipop stick in the melted chocolate, then insert it upright into the Nutella balls. Repeat with all the rest.
• If the Nutella balls start to soften up, return back to the freezer for a few minutes until firm again.
• Holding by the stick, start dipping the balls in the melted chocolate, one at a time.
• At this point, you could start pressing on the crushed hazelnut praline, if using, before the chocolate starts to harden up.
• Place the pops on the lined baking sheet, with the balls facing down.
• Let cool at room temperature or in the fridge until the chocolate shell sets.
• If desired, transfer any remaining melted chocolate to a piping bag or zipper lock bag and snip its end with scissors to start decorating. Add swirls, drizzles or any design of your choice. Alternatively, a fork can be used to create more random but equally pretty drizzles.
• Let the decorations set, then place in mini cupcake liners to serve. Enjoy immediately or store in the fridge, covered, for a week.
• For the molten effect, let the pops come to room temperature before serving. The pops also taste great cold straight from the fridge; they won't ooze out though.

TO MAKE THE HAZELNUT PRALINE:

• Line a baking sheet with a silicon mat or generously buttered foil. Keep nearby.
• Place the sugar and water into a saucepan over medium high heat, swirling the pan until sugar is dissolved.
• Boil rapidly until the syrup turns a rich golden brown.
• Remove the saucepan from the heat and stir in the hazelnuts.
• Pour over the prepared baking sheet.
• Let cool completely until it firms up into a brittle like caramel.
• Place the praline in a zipper lock bag and seal. Using a meat tenderiser, hammer or rolling pin, crush the praline into small pieces but not powder. Set aside until ready to use.