The custard cream is one of the most popular biscuits here in the UK. 2 custard flavour biscuits wedged with a custard flavour buttercream, perfect for dunking in a cup of tea or coffee normally. But lets try to make the biggest one in the World! Yep, a giant custard cream. Using 64 times the amount of dough for a normal one – amazing for a Birthday cake alternative!
First thing you want to do is get two large baking trays, line them with baking parchment and put to one side. Make sure you have enough room in your fridge for them! Beat together the butter and sugar until combined, then add the other wet ingredients -the extract and the milk and again mix through. Add the custard powder and flour, beat initially, but you may find it easier to put onto a chopping board with some flour to knead it briefly until smooth. Try to get it into a big ball.
Press the dough evenly into the baking tray making sure it is evenly spread out and smooth. Do no bake this right away, the dough needs to chill for at least 30 minutes to stop movement when baking. So stick the tray in the fridge. Repeat with 2 more batches of dough, except the 3rd batch, just wrap in some cling film and keep in the fridge rather than on a tray.
Preheat the oven to gas 4, 180ºC, fan 160ºC.
With the third dough ball, roll out small tubes and cut to size to help make the lettering / shapes on the custard cream. Just use a standard custard cream or google a custard cream image for reference. You don’t need to stick it down, as it’ll join during baking. I found it best to sketch out where I was planning to put the shapes before placing them there. Once your design is done, put it back in the fridge for 30 minutes to firm up.
Bake the biscuits for 15-20 minutes until just starting to brown around the edges. This dough is a typical custard cream dough and is very weak, it will get stronger as it cools so leave it to cool fully in the baking trays respectively. If you want it harder bake for longer although it is likely to brown / be more crunchy and less authentic. Foil could be used to stop it burning but keeping to the steps above makes it taste melt in the mouth and super authentic!
Whilst the biscuits are cooling down make the filling. Cream together the icing sugar, butter, custard powder and vanilla extract with a wooden spoon until smooth. Dollop the filling onto one cooled half (the non design side unless you want to do the design both sides!) and place the design side biscuit on top. Be careful when doing this as they are delicate even when cooled, the video shows how I got the out the pans by flipping onto a board. Seal the edges with additional buttercream if needed and smooth out where needed. Slice up and store in an airtight container for up to 10 days!