The first step in creating these decadent puddings is to preheat your oven to 220°C (425°F/Gas 7), ensuring it's ready to bake the puddings to perfection.
Take a tablespoon of caster sugar and sprinkle it inside each greased ramekin, tilting and turning the ramekin to coat the sides evenly. Transfer any excess sugar to the next ramekin and repeat the process until all are well-coated, creating a sugary shell for the puddings.
In a saucepan over medium heat, combine butter, a shot of espresso, and chopped dark chocolate, stirring until the mixture is completely melted and smooth. You can also melt the ingredients together in a microwave for the convenience.
Beat eggs with 110g of caster sugar in a separate bowl until the mixture is pale and fluffy. Gradually blend this egg mixture into the melted chocolate. Gently fold in half the grated orange zest and all the ground hazelnuts to incorporate them fully into the batter.
Evenly divide the batter among the prepared ramekins, placing them on a baking tray. Bake in the preheated oven for about 15 minutes. The goal is a pudding that's set and firm to the touch but with a delightfully molten center.
Once baked, present the puddings hot, garnished with the remaining orange zest. Accompany each pudding with a choice of ice cream, Greek yogurt, or crème fraîche. For an extra special touch, consider adding a scoop of vanilla ice cream swirled with high-quality marmalade, re-frozen to just the right consistency, alongside the pudding.