Preheat the oven to 180ºC/160ºC fan and grease 2–3 doughnut moulds (this recipe makes 12–15 bronuts). Place the prepared moulds on baking trays.
Melt the dark chocolate and unsalted butter together in a microwave-safe bowl until smooth.
In a separate bowl (a stand mixer or electric hand whisk works best), whisk the eggs and caster sugar for 8–10 minutes until the mixture has doubled in volume, is paler in colour, and has a mousse-like texture.Gently fold the melted chocolate mixture into the egg mixture.
Add the plain flour, golden syrup, vanilla extract, and cocoa powder, and fold again until fully combined.
Transfer the brownie batter into a large piping bag and pipe evenly into the prepared doughnut moulds.
Bake for 16–18 minutes, then leave the bronuts to cool completely in the moulds. Once cooled, chill them in the fridge or freezer for about 3 hours to set.
When set, remove the bronuts from the moulds. Melt the milk chocolate in a small microwaveable bowl. Dip each bronut into the milk chocolate and add a milkybar button into the middle of each bronut.
Finish by decorating with edible eyes and Smarties to create the cute penguin faces. Enjoy!
