Preheat oven to 190 degrees celcius.
In a large bowl, cream together the butter, peanut butter, brown sugar, and white sugar until smooth.
Beat in the eggs one at a time, then stir in the corn syrup, water, and vanilla. In a separate bowl, sift together the flour, baking soda, and salt; and stir into the peanut butter mixture. Fold in chocolate chunks.
Using an ice-cream scooper, drop spoonfuls of dough about 3/4 inch apart - and using a fork flatten slightly. Alternatively, let you children have fun with the dough and let them have fun in the kitchen
Bake for 10 to 12 minutes in the preheated oven, or until edges are golden. Allow cookies to cool on the cookie sheet before removing them.