Pre-Heat oven to 180C.
Lightly grease and line a 24cm square cake pan with baking paper. Melt the butter in a saucepan over a low heat.
Remove from the heat once melted, stir in the sugar, eggs, cocoa and vanilla.
Stir in cauliflower flour and salt, and add chopped chocolate and pecans, and stir through.
Pour into prepared tin and bake for 30 minutes.