Fruit & Nut Double Ginger Cookies

This is the first recipe tried from a new book - One Smart Cookie. It's a low-fat baking book, but not one full of strange ingredients, or recipes you wouldn't want to eat. It also doesn't use artificial replacements for normal ingredients; if you want sugar, you have sugar, not some chemical replacement. My only problem with the book - and it's not a big one - is that being an American/Canadian book, all of the measurements are in cups. Being British, I'm more used to grams/ounces.
Anyway, the recipe I tried was Fruit & Nut Double Ginger Chews. I made a small change to it - not having molasses, I used a mixture of golden syrup and black treacle. Not sure if I got the proportions quite right; I'll have to wait until I get comments from others who try the cookies.

Recipe:
1/4 cup unsalted butter, softened
1/2 cup caster sugar
1/4 cup golden syrup
1/2 cup black treacle
1 large egg
2 cups flour
1 tablespoon cocoa powder
1 teaspoon ground cinnamon
1 teaspoon ground ginger
1/2 teaspoon bicarbonate of soda
1/2 teaspoon salt
1/2 cup raisins
1/3 cup walnuts, chopped
1/4 cup crystallized ginger, finely chopped

Preheat oven to 175C. Line some baking sheets with non-stick baking parchment.
In a large bowl, cream together the butter and sugar. Add the egg, then the the golden syrup and treacle. Mix thoroughly.
In another bowl, combine all of the dry ingredients.
Gradually add the dry ingredient mixture, a couple of tablespoons at a time, to the wet ingredients. Stir between each addition to ensure everything is well combined.
Drop large spoonfuls (level tablespoons/heaped dessertspoons) of the mixture onto the baking sheets, making sure they have room to spread. Bake for 12 to 14 minutes, until set.
Unless you have a large oven, you'll probably have to bake these in multiple batches.