Line a baking tray with a sheet of non-stick baking paper. Place the sliced bananas on the lined baking tray in a single layer. Pop in the freezer for 2 1/2-3 hours — until frozen.
When you're ready to make the ice cream, remove the bananas from the freezer and leave to soften for 5 minutes. Cut out a 15cm diameter disc of non-stick baking paper, and set aside.
Place the bananas in a food processor or blender and blitz for a minute or two until thick, pale, smooth, and creamy. Depending on the size of your food processor or blender, you may need to do this in two batches.
Working quickly, scrape into a medium mixing bowl using a spatula. Place the Biscoff spread in a cup and stir to loosen up slightly, then quickly scrape into the frozen banana mixture. Add the biscuit pieces, meringue chunks, pecans, and chocolate chunks or (chips). Using a large metal spoon, fold in your additions — until the ingredients have swirled through the banana mixture to give a slightly marbled effect.
Working quickly, scrape the mixture into a 1L freezer-safe pudding basin and level the surface. Lay the non-stick baking paper disc on the surface of the ice cream, then immediately pop in the freezer. Freeze for a minimum of 4 hours, or until completely solid in the centre.
When you’re ready to dish up, place a serving plate in the fridge to chill for about 10 minutes. Half-fill a large heatproof bowl with some boiling water. Take the frozen pudding from the freezer, remove the paper disc, and carefully dip the pudding basin into the hot water for about 10-15 seconds, taking care not to let the water spill over onto the pudding. This should loosen the frozen pudding from the pudding basin. Quickly dry the outside of the pudding basin.
Place the chilled serving plate upside down over the pudding basin, then — holding both the plate and the pudding basin — quickly turn over to get the frozen pudding in place on the plate. If the pudding doesn’t release, dip the pudding basin in the boiling water for a further 10 seconds, quickly dry the outside of the pudding basin, then turn the pudding out onto the plate.
Quickly pour the chocolate sauce over the top of the pudding, letting it run down the sides. If you're adding pecans to your pudding, you can sprinkle these on top. Then voila!