Preheat oven to 180°C (fan assisted). Line a 27 cm x 18 cm slice cake tin with baking paper.
Step 2
Mix together the flour, baking powder, brown sugar and melted butter. Press evenly into the bottom of the prepared tin. Bake for 12 minutes or until the base is a light golden colour. Remove from the oven and set aside in the tin while preparing the filling.
Step 3
In a saucepan, add the sweetened condensed milk, butter, golden syrup and Gregg's Ground Ginger. Stir over medium heat until almost boiling, it will thicken during heating.* Pour the filling over the shortcake base, carefully spreading to cover the base. Return to the oven and bake for a further 12 minutes. Remove from the oven and cool in the tin. Carefully lift out and place on a wire rack.
Step 4
Melt the white chocolate in a heatproof bowl over hot water or in the microwave for 20 second bursts. Spread over the cooled filling.
Step 5
Scatter the chopped crystallised ginger over the chocolate. Refrigerate until set. Cut into slices. Store in an airtight container.
Tips
*It's important to stir the caramel during heating to prevent lumps forming and it catching on the bottom of the saucepan. This can also be done in a bowl over simmering hot water if wished.