Preheat oven: 180°C / 160°C (fan) / Gas Mark 4 / 350°F.
In a mixing bowl, beat the oil, eggs, sugar, vanilla and milk together until fully combined.
In a separate bowl, sieve in the cocoa powder, flour and baking powder and whisk together.
Gradually pour the wet ingredients into the dry, stirring together as you pour until just combined. There may be a few small lumps left, but that’s ok.
Slowly add the hot coffee into the cake batter, mixing as you pour, until the liquid has only just combined, then stir in the Bailey’s Irish cream.
Divide the mixture evenly between the two greased and lined 8-inch cake pans. Bake for 25-30mins until risen, springy to the touch and a skewer comes out clean. Allow the cakes to cool in the tins for 15mins before moving to a wire rack to cool further.