Preheat your oven to 180C/160C Fan, and line a 9x9" square tin with parchment paper!
Add your butter and dark chocolate to a bowl, and melt until smooth - I use the microwave on 30 second bursts. Alternatively, add them to a pan and melt till smooth. Leave to cool.
Add your eggs and sugar to a large bowl, I use my stand mixer, and whisk for a few minutes until the mixture has doubled in size, is alot paler, and leave a trail for a few seconds when you lift the whisk out of it. It needs to be a thick mousse!
Carefully fold in your cooled chocolate mix, and then carefully fold in the flour, cocoa powder, and spices.
Once everything is folded in - add in your chocolate chips, and fold again.
Pour the mixture into the tin, and bake in the oven for 25-30+ minutes until baked through. Sometimes it can take a bit longer.
Once baked, leave to cool in the tin.
Once cooled, I drizzle on my melted chocolate, and add a mini gingerbread man for each slice, and some gingerbread crumbs!
I store these at room temperature so that they don't dry out!
The decoration is completely optional.
Some brownies can take longer to bake in some ovens as mentioned in the post - if they are extremely under-done at 30 minutes though, you probably over mixed the mixture.