Line a 20cm x 30cm (8×12 inch) baking tray with baking paper and preheat oven to 180C (355F).
In a large bowl sift in the sugar, flour, baking powder, ginger and salt. Add the rolled oats and whisk until well combined. Rub the finely diced butter into the mixture with your finger tips (alternatively, place all base ingredients in a food processor and whiz until the mixture is combined).
Press the mixture into prepared pan and bake for 25 -30 minutes or until golden. Set aside.
Melt the butter and golden syrup in a medium saucepan. Once melted, sift the icing sugar and ground ginger and mix until smooth. Pour/spread the topping onto the base and smooth out with an off-set spatula. Cut into squares and enjoy!