Line 2 large baking trays. Place the peanut butter and caster sugar in a large bowl and mix together until all the sugar is mixed into the peanut butter. Add the eggs and Vanilla Extract and beat together until the mixture is all combined.
Finally fold in the Chocolate Chunks. Bring to dough into a ball and divide into 15 equal pieces. Roll each pieces of cookie dough into a ball and place on the prepared baking tray spaced slightly apart. Flatten each ball of dough slightly and place in the fridge to chill for 30 mins.
10 minutes for baking, preheat oven to 180°C/160°C/Gas Mark 4. Once the cookies have chilled bake in the oven for 15-20 minutes until golden brown and still slightly soft, they will firm up as they cool. Leave the cookies to cool on the baking trays for 15 minutes and then transfer to a wire rack to cool completely.
Your cookies are now ready to enjoy! They will keep in an airtight container for 3-5 days.