Prepare Your Workstation: Line a large baking tray or a couple of large plates with baking parchment. This is essential to prevent the balls from sticking.

Make the Peanut Butter Mixture: In a large mixing bowl, combine the smooth peanut butter, sifted icing sugar, melted unsalted butter, vanilla extract, and fine sea salt. Use a sturdy wooden spoon or a spatula to mix everything together until it's well combined and forms a thick, dough-like consistency. At first, it might look a bit crumbly, but keep mixing and it will come together.

First Chill: Cover the bowl with cling film and place it in the refrigerator to chill for at least 30-45 minutes. This step is crucial as it firms up the mixture, making it much easier to roll into balls.

Roll the Balls: Once chilled, remove the mixture from the fridge. Scoop out portions using a teaspoon or a small cookie scoop (about 2-3cm in diameter). Roll each portion between the palms of your hands to form a smooth ball. Place the rolled balls onto your prepared baking tray.

Second Chill (The Important One!): Place the tray of rolled peanut butter balls into the freezer for at least 1 hour, or in the refrigerator for 2 hours. They need to be very firm and cold. This prevents them from melting or falling apart when you dip them into the warm chocolate. I used to struggle with this dish until I discovered that a proper freeze is the secret to a perfect coating.

Melt the Chocolate: Just before the chilling time is up, prepare the chocolate coating. Place the chopped dark chocolate and the optional coconut oil in a microwave-safe bowl. Microwave in 30-second bursts, stirring well between each one, until the chocolate is almost completely melted. Stir until smooth. Alternatively, melt the chocolate in a heatproof bowl set over a saucepan of barely simmering water (a bain-marie).

Dip the Balls: Working quickly, remove the peanut butter balls from the freezer. Drop one ball at a time into the melted chocolate. I find that using two forks works best: one to lift the ball out of the chocolate and the other to help scrape off the excess from the bottom. This gives you a neater finish.

Final Set: Place the chocolate-covered ball back onto the parchment-lined tray. If you're using it, immediately sprinkle a few flakes of sea salt on top before the chocolate sets. Repeat with the remaining balls.

Final Chill: Let the chocolate peanut butter balls sit at room temperature for about 30 minutes or place them in the refrigerator for 10-15 minutes until the chocolate shell is completely firm and set.