Oreo cake will make you very popular, with rich chocolate sponge, crunchy Oreo buttercream filling and simple Oreo decoration. This cake is a showstopper.
If you're making this cake for a special occasion, we'd recommend making it the day before or ahead of time so the first layer of buttercream has plenty of time to set. This will ensure a smooth buttercream finish.
If you want to make this cake even naughtier, cover in chocolate buttercream or even ganache instead and decorate with crushed Oreos.
Grease and line your tins and preheat the oven to 160C/gas 3. Cream the Trex and sugar together, then add the eggs and beat with an electric whisk until light and fuffy. Sift all the dry ingredients into a separate bowl. Beat the dry ingredients into the creamed Trex, sugar and eggs gradually, alternating with the buttermilk. Add the vanilla and mix until evenly mixed. Add the vinegar and mix.
Divide the mixture between 3 tins. Bake the cakes in the oven for about 25 minutes, depending on your oven. Remove from the oven and cool the cake in the tins for 10 minutes, then leave to cool completely on a wire rack.
To make the buttercream, beat the butter, then add the vanilla and beat again. Add the sifted icing sugar bit by bit and beat until smooth. Add 2 tablespoons boiling water to loosen the mixture so itís easy to spread.
Once the buttercream is smooth, you can whiten it a little with a touch of lavender food colour, just a touch on the end of a cocktail stick a bit at a time until itís nice and white.
Crush the large Oreos in a sandwich bag using a rolling pin. You want the pieces to be quite small.
Add the smashed Oreos to a third of the buttercream and mix well.
Add a touch of buttercream to the cake card to help the cake stick.
Layer the cakes with the Oreo buttercream and then cover the whole cake with a thin layer of buttercream, using the cake cards as a guide and pop in the fridge for 1 hour to set.
Once the first layer of buttercream has set, you can add the second layer. This just stops the cake crumbs showing in the buttercream.
Finally, split the mini Oreos and decorate the buttercream with them.
Your cake is now ready to serve!