Had these recently at a Pampered Chef party - they were divine!
200g unsalted butter; 200g dark chocolate (min 50%); 3 large eggs; 200g caster sugar; 110g plain flour; 100g chopped walnuts, pinch salt; 1dsp vanilla extract (optional)
Melt choc & butter together; mix eggs, sugar & vanilla in another bowl & add flour & salt; add the chocolate mixture and chopped nuts.
Pour into greased/lined baking tray (medium sized!), bake for approx 25 mins (until lightly brown and springy in middle); 180C/160C Fan/ Gas 4
Hope this makes sense and that they turn out OK! They are good cold or served warm with vanilla icecream.