Preheat the oven to 180C. Grease and line a 20cm square baking tin with baking paper.
Add the softened butter and golden caster sugar into a large mixing bowl. Beat for a few minutes until it’s creamy.
Add in the eggs, self-raising flour, cocoa powder, and milk. Beat until it’s well combined.
Add the mini chocolate orange segments and fold them through.
Pour the batter into the baking tray and spread it evenly into the edges.
Bake it for 30 minutes, or until a skewer comes out clean.
Leave it to cool in the tin for about ten minutes, then transfer it to a cooling rack to cool completely.