This recipe is from Stoked, and makes the real deal, an old-skool proper buttery, crunchy, gingery slice. moreish in the extreme, finger-lickin' good! I tweak it with the addition of a bit of semolina which gives a slightly more textured base.

115g butter
1/2 C sugar (I use caster)
3/4 C flour
2 Tbs semolina
1 tsp baking powder
1 tsp ground ginger

pre-heat overn to 180C, butter & baking-paper-line a 30x20cm slice tin.
cream butter and sugar till light and fluffy. Sift flour, baking powder and ginger, add semonlina and mix, then mix into the butter/sugar. it will be crumbly mix, a bit like a loose pastry
press into the tin, to form a flat base
bake for 20-25 mins until the base is firm to touch. remove from oven; keep warm for icing.

4 Tbs butter (about 60g)
1/2 C icing sugar
1 Tbs golden syrup
2 tsp ground ginger

combine all in a small saucepan, and heat, stirring, until melted and completely combined. Pour over warm base, and spread out evenly.
cut the crunch before it is fully cooled/icing fully set... the best is a warm wet knife

Footnote: Frances also made this recipe with Ginny's twist and the crunch is TO DIE FOR!