Marshmallow & Butterscotch bars

This is yet another recipe from The Hummingbird Bakery, I can't get enough of this book it's called "Cake days" and it's the best cook book I own and I have a fare few!

Here is the recipe and method
For the base
150g flour
40g icing sugar
120g unsalted butter, softened

For the topping
100g pink and white mini marhsmallows
210g caster sugar
150g soft light brown sugar
190g golden syrup
70g unsalted butter
60ml double cream
1 teaspoon vanilla essence
60g crunchy peanut butter
30g mixed chopped nuts (I only had pecans so went with that this time)

Preheat the oven to 170C; grease and line a 22cm x 31cm baking tray.
Mix the ingredients for the base until a dough forms (by hand or with an electric mixer using the paddle attachment).
Press the dough into the prepared baking tray, making a slight lip around the edge and bake for 20 minutes or until the edges are a light golden brown and the middle is pale but cooked.
Place the marshmallows on top of the baked base, spreading them out evenly.
Place both types of sugar with the golden syrup and 240ml of water and bring to the boil.
Allow the mixture to boil until the sugar reaches the soft-ball stage (see notes below and picture above).
Remove from the heat and stir in the butter.
Bring the butterscotch back up to the boil and allow to bubble away for approximately 3 minutes.
Take the pan off the heat and stir in the double cream, vanilla essence and peanut butter.
Stir continuously until the peanut butter has melted.
Pour the mixture on to the base and sprinkle the chopped nuts on top.
Allow to set at room temperature for a few hours or preferable overnight.
Slice into bars and serve.
These bars are lovely great for picnics!