Giant White Chocolate and Raspberry Cookies

My other half is a massive fan of Tesco Finest White Chocolate and Raspberry Cookies, often devouring all 5 in the packet before anyone else gets a look in!     In an attempt to recreate them i've tried several recipes but they've always come out slightly too dry and cakey or so underbaked they're raw in the middle .  With this recipe I've finally cracked it, these cookies are soft and chewy without that raw doughiness.  You can add whatever you like to the basic cookie dough, I'm going to try salted caramel and pecan nuts next!

For the Cookie Dough :
 125g soft butter
100g baking spread (I always use Stork)
100g caster sugar
125g brown sugar
200g condensed milk
1tsp vanilla extract
1/2 tsp strawberry flavouring (optional)
325g plain flour
15g cornflour
1 tsp baking powder
100g white chocolate, roughly chopped
75g raspberry dried fruit pieces (I used Fruit Flakes or you could also use raspberry flavoured cranberries although these are harder to find!)

Preheat the oven to 180 degrees C / 350 degrees F.
Line two baking sheets with greaseproof paper.
Cream together the butter, baking spread and both types of sugar til just combined.  You don't need to beat in lots of air as you do when making a cake as these cookies don't need to rise, overbeating can give a more cakey texture rather than chewiness.
Beat in the condensed milk, vanilla extract and strawberry flavouring (if using) followed by the flour, cornflour and baking powder.
Gently fold in the white chocolate chunks and raspberry pieces so they are evenly distributed.
Divide the dough into 12 equal balls and place 6 on each baking sheet.  I used an ice cream scoop to do this as it makes it very easy to ensure each cookie is the same size.  You don't need to flatten them as they will spread during baking, just ensure they are spaced well apart.
Bake for 10 - 15 minutes until baked to your liking.  10 minutes gives very soft, doughy cookies.  15 minutes will give you much firmer cookies with crispy edges and just a little bit of chewiness in the centre.  My personal preference is 13 minutes, just cooked enough to not fall apart but still super gooey and yummy in the middle!
Allow the cookies to cool on the tray before removing by sliding a palette knife underneath them.