• Preheat oven to 180°C (350°F) if using a conventional oven or 160°C (320°F) if using a fan-forced oven. Line 2 baking trays with parchment paper.

Make the chocolate biscuits

• If using a food processor: Add all the ingredients to a food processor and blitz until combined. The mixture should be slightly crumbly but will come together if you pinch some of the mixture between two fingers. If the mixture is a little soft, add more flour and pulse again. If it's a little dry, add a dash of milk and pulse until combined.
• If making by hand: Add all the dry ingredients to a large bowl and mix until combined. Add the butter and malt syrup and cut the ingredients together with a pastry cutter or two knives until you get a soft dough.
• Dust a clean work surface with flour. Roll out the dough to about 4mm (a little less than 1/4-inch) thick. Cut the dough into even rectangles, approximately 6 x 3cm (2.5 x 1.25-inch) large. Collect the excess dough, and repeat until you’ve used up all the dough.
• Arrange the biscuits on your baking trays, with a little space between each (they don't really spread). Bake for 13-15 minutes or until they look fully baked and their surface looks and feels dry but soft. The biscuits will continue to bake on the trays as they cool down. If your biscuits change shape after baking, you can use a knife to reshape them while they are still warm. Let the biscuits completely cool on their trays.

Make the filling:

• Add the butter to a large bowl (if using a hand mixer) or the bowl of a stand mixer. Beat until it's light and fluffy.
• Add the sugar, cocoa powder, malt extract and vanilla and beat the mixture on low speed until just combined. Increase the speed to high and beat until light and fluffy. For a firmer filling, add more sugar. For a slightly softer filling, add a dash of milk (be careful not to add too much milk as the filling needs to withstand the heat of the chocolate).

Assemble the vegan Tim Tams:

• Place half of the biscuits upside down (so their rough side is facing up). Use a piping bag or small spatula/knife to pipe or spread the filling on the biscuits. The filling should be approximately 5mm thick (1/4-inch). Sandwich with the remaining biscuits. Place the Tim Tams in the fridge or freezer to firm up for at least 1 hour.
• When your biscuits are cold and firm, melt the chocolate in a double-boiler. If your chocolate is a little thick, add the oil and mix thoroughly. Allow the chocolate to cool down slightly.
• One by one, dip the cold biscuits in the chocolate, allowing excess chocolate to drip off. Arrange the coated biscuits on a lined baking tray.
• Allow the Tim Tams to set at room temperature or in the fridge for at least 30 minutes (see note 5 for some decoration tips).

Storing the Tim Tams:

• Store the Tim Tams in an airtight container at room temperature for 1-2 days or in the fridge for up to 2 weeks. They also keep well in the freezer for up to 1 month, although the chocolate coating may bloom.