Line a 9-inch (23-cm) square metal baking pan with plastic wrap, allowing the wrap to hang over about 4 inches (10 cm) on 2 opposite sides. Smooth the plastic wrap so that it fits the contours of the pan and is as unwrinkled as possible.
Using a rubber spatula, spread the softened ice cream in the prepared pan, smoothing it evenly. Fold the overhanging plastic wrap over the ice cream, then wrap the pan securely with more plastic wrap. Freeze until firm, at least 2 to 3 hours.
Line a baking sheet with parchment paper. Remove the pan from the freezer and unwrap the outer layer of plastic wrap. Using the overhanging plastic wrap, lift the slab of ice cream out of the pan and place it on a cutting board.
Grab a long, sturdy knife and cut the ice cream into 8 equal rectangles. Use a metal spatula to separate the rectangles and transfer them to the prepared baking sheet, spacing them at least 2 inches (5 cm) apart. Insert a wooden popsicle stick into a short side of each rectangle. Cover the baking sheet with plastic wrap and freeze until firm, at least 2 to 3 hours.
In a heatproof bowl, combine the chocolate and oil. Place over but not touching a pan of barely simmering water and heat, stirring gently, until the chocolate melts and the mixture is smooth. Remove from the heat and let cool, stirring occasionally, until the mixture is barely lukewarm, 15 to 30 minutes.
Place your desired toppings in separate bowls. Remove the ice cream bars from the freezer. Working quickly, lift 1 bar by its stick. Dip the ice cream bar in the chocolate, turning to coat the ice cream partially and letting any excess chocolate drip back into the bowl. Sprinkle with the topping. Return the bar to the baking sheet. Repeat with the remaining ice cream bars.
Freeze the ice cream bars, uncovered, until the ice cream and coating are firm, at least 2 to 3 hours. Consume immediately or wrap each bar individually in plastic wrap and return to the freezer. Originally published August 30, 2016.