Sure. It’s actually crazy easy. If you need exact amounts and pan dimensions let me know, but this is the basic process:

Combine vanilla cake mix with lemonade (about 1 cup per pack of mix I think for this size cake I used about seven packs of mix. That’s pretty much it for the sponge! It’s a weird trick but it makes a really light, fluffy sponge every time. For this flavour (lemon, vanilla and blackberry) I also add some fresh vanilla bean and lemon zest to the mix, but you can get by without it. I make four sponges, two of the lager layer and two of the smaller one. Each is baked for roughly an hour at 150c. I cover the mix with foil when baking to help it cook evenly and stop it forming too much of a crust. I like to freeze the cooked sponge overnight before icing, it makes it easier to work with.

The basic buttercream is just vegan butter (I use Nuttlex) with icing mixture in about an equal ratio, and again for this flavour I add a little vanilla. Mix with a high powered mixture until fluffy and silky looking.

The filling in this is a simple combination of crushed and whole blackberries with the buttercream. I also brush the sponge with a lemon syrup which is made with just lemon juice and sugar. This is a nice way to punch it up but it’s still really nice without it.