Preheat the oven to 200 degrees celsius (fan forced). Line two flat baking trays with baking paper and set aside.
Sift the self raising flour and baking powder into a bowl.If using a Thermomix: Mix for 10 seconds, Speed 5. Scrape down the sides of the bowl.
Add the butter and rub it into the flour using your fingers until it resembles fine breadcrumbs. If using a Thermomix: Add the butter (chopped) and mix for 8 seconds, Speed 6, or until fine breadcrumbs remain.
Add the sultanas, caster sugar, grated orange zest, eggs and vanilla extract and mix until combined and a firm dough forms. If using a Thermomix: Add the sultanas, caster sugar, grated orange zest, eggs and vanilla extract and mix for 8 seconds, REVERSE, Speed 2. Scrape down the sides of the bowl and repeat until combined.
Place heaped teaspoonfuls of the mixture onto the prepared baking trays (leaving a 5cm gap to allow for spreading).
Bake for 12-15 minutes or until golden brown. Allow to cool on the trays for 5 minutes before transferring to a wire rack to cool completely.
Notes
RECIPE NOTES & TIPS
Texture - rock cakes have a crumbly, dry texture that is a cross between a scone and a biscuit.
Rock cakes are deliciousserved while still warm.
Use cold butter - this ensure the rock cakes have a light and fluffy texture.
Check that your baking powder is within its use-by date - otherwise it won't be as effective.
Preheat your oven and make sure it is to temperature before baking your rock cakes - they need that immediate burst of heat to help them rise.
Leave a gap in between the rock cakeson the trays - as they can spread when in the oven.
Don't overcook rock cakes - they will firm up as they cool.
Sprinkle over a little sugar before baking - for an extra crunchy top!
Storage - best served on the day they are made, however you can store them in an airtight container at room temperature for up to 3 days.
Freeze - for up to 3 months. Thaw in the fridge overnight and reheat in a low oven.