Makes 16

170g unsalted butter

180g dark chocolate

3 Large eggs

150g castor sugar

1 tsp vanilla

190ml cake flour

30ml cocoa powder

Pinch salt

60ml instant espresso powder

100g dark chocolate, roughly chopped

100g toasted pecans

Nutella for topping (optional)

Preheat oven to 180C.

Melt together butter and dark chocolate.

Whisk the eggs, sugar and vanilla until light and airy.

Mix the melted chocolate mixture into the whisked egg mixture.

Sift together flour, cocoa, salt and instant espresso powder.

Fold the dry ingredients into the wet ingredients, being careful not to over-mix.

Fold in the chocolate and nuts then transfer to a greased square baking tin

Bake for 25 – 35 minutes.

Leave to cool in the tin for 5 minutes, then remove from the tin and cool on a cooling rack until completely cool.

Spread with Nutella, if using, then cut into 16 portions.