A rich and irresistible biscuit with a lovely peanuty flavour and a crumbly texture that will keep you coming back for me.  Seriously addictive. 

The lowdown:

Getting it together:                     20 minutes
Cooking it:                                10-12 minutes
Oven set to:                              190c/375f/Gas 5
Makes:                                     About 18 cookies
Gear needed:                            2 baking sheets

What you need:

125g    Unsalted butter
90g      Dark brown sugar
125g    Crunchy peanut butter – more if you’re going to eat some out of            the jar
1 egg
1 tsp    Vanilla extract
180g    Self-raising flour
½ tsp   Salt
125g    Dark continental chocolate

A choc-chip off the old block:

• Cream the butter and sugar together until the mixture is light and fluffy.  Blend in the peanut butter. 
• Then mix the egg and vanilla together and gradually beat into the creamed ingredients.
• Sift the flour and salt together, then fold that into the mixture.
• Chop the chocolate into small pieces and stir that in.
• Put heaped teaspoons of the mixture about 3 or 4 cm apart on the lightly greased baking sheets.  Flatten the mixture with the back of a wet spoon.
• Bake for 10-12 minutes.  Allow to cool on a wire rack.