Line 2 round 20 cm/8 in cake tins with greaseproof paper.
Mix together oil, milk, caster sugar, and eggs in a large bowl.
Combine the dry ingredients in another vessel and gradually add the liquids to it, mixing until smooth.
Divide between the two tins and bake for 35-40 min(??) until they pass the skewer test. Leave to cool in the tins for a little bit then transfer to a cooling rack (remove the paper while slightly warm)
If possible, slice the two cake halves in half again to make 4 layers.
Whip cream with a little bit of sugar until solid enough for a filling. Fill the layers with jam and cream.
Dust with icing sugar.
Notes
My written notes had this listed as "world's most Slop batter but it's fine & tasty." It really is a LOT of oil. It does work though.
OG suggests adding frozen raspberries to the jam and mixing the jam in with the cream, but you could literally just use non-seedless jam and it's the same. Also, the first time i made this i used rasp jam and chocolate buttercream and it was pretty good.
Full batter amount can also be used to make exactly 24 cupcakes. Consider using 1/3 or 2/3 amounts.