Preheat oven to 180C and line baking trays with silicone paper.
In a food processor cream sugar and butter until pale.
Add egg and vanilla and whiz until just incorporated.
Add remaining ingredients and whiz until just combined.
Roll dessert spoon worth of dough into rounds, then push your thumb into the ball to create a dent. Spoon a little jam into the dent.
Allow 3cm for spreading between the biscuits.
Bake for 10 – 15 minutes. Allow to cool on the trays.
Notes
This biscuit dough freezes really well.
I make a double batch with half going in the oven and half being frozen in a single layer after the thumb print step, but before the jam is dolloped on.
After the biscuits are completely frozen they can then be stored in a container in the freezer. When you need some biscuits (say when you know someone is popping in) just preheat oven, put frozen biscuits on a lined tray, dollop on jam and bake for 5-8 minutes longer than recipe.
Hazelnut meal is found at most major supermarkets, health food shops or online. Or you could make your own.
Simply pulse hazelnuts in a food processor until you have a fine breadcrumb texture. I would recommend sieving you hazelnut meal to remove any inconsistency.