Step 1: Make the Truffle Filling

1. In a medium saucepan, heat the heavy cream over medium-low heat until it begins to simmer gently (do not boil). Remove from heat.
2. Add the Nutella to the warm cream and whisk until smooth and fully combined. The mixture should be glossy and creamy.
3. Stir in the vanilla extract and salt (if using) to enhance the flavor.
4. Transfer the mixture to a shallow dish or bowl, cover it with plastic wrap (pressing the wrap directly onto the surface to prevent a skin from forming), and refrigerate for 2 hours, or until the mixture is firm enough to scoop.

Step 2: Form the Truffles

1. Once the Nutella mixture is firm, use a small cookie scoop or spoon to portion out about 1 tablespoon of the mixture. Roll it between your palms to form a smooth ball.
2. Place each truffle on a baking sheet lined with parchment paper or a silicone mat. Repeat until all the mixture is used.
3. If the truffles become too soft while rolling, place the baking sheet in the refrigerator for 15–20 minutes to firm them up again.

Step 3: Prepare the Chocolate Coating

1. Melt the chopped chocolate and coconut oil (if using) in a microwave-safe bowl in 20–30 second increments, stirring after each interval until smooth and fully melted. Alternatively, melt the chocolate using a double boiler on the stovetop.
2. Allow the melted chocolate to cool slightly before coating the truffles to prevent melting the filling.

Step 4: Coat the Truffles

1. Using a fork or dipping tool, dip each truffle into the melted chocolate, ensuring it is fully coated. Tap the fork on the edge of the bowl to remove any excess chocolate.
2. Place the coated truffle back on the parchment-lined baking sheet.
3. If desired, immediately sprinkle the truffle with toppings (crushed hazelnuts, sprinkles, or cocoa powder) before the chocolate hardens.
4. Repeat with the remaining truffles.

Step 5: Let the Truffles Set

1. Once all the truffles are coated, place the baking sheet in the refrigerator for 15–20 minutes to allow the chocolate coating to set completely.
2. Once set, transfer the truffles to an airtight container. Store them in the refrigerator for up to 1 week or in the freezer for up to 2 months.