Into a large mixing bowl, add the (slightly cooled) melted butter, oil, condensed milk, vanilla extract, eggs and both sugars and beat well using a whisk/whisk attachment until well combined and light and airy.
Add the flour, cocoa powder, bicarbonate of soda and sour cream and beat well until smooth
Finally, mix in the boiling water until silky and smooth
Divide the batter into the two tins
Bake in the oven for 40-45 mins until cooked right through
Leave to cool in the tins
Meanwhile make the frosting:
Melt the chocolate and leave to cool
In a large bowl beat the butter until smooth
slowly add the icing sugar, a little at a time to make a smooth mixture
add the cocoa powder, condensed milk , vanilla and the cooled chocolate and beat well.If the mixture is still a little thick, add a little more condensed milk
*assembling the cake*
Sandwich the sponge with ⅔ of the frosting
spread the remaining frosting on the top of the cake
add the chopped fudge for decoration.
Recipe by Mummy Mishaps at http://www.mummymishaps.co.uk/2018/03/chocolate-fudge-cake.html