Preheat oven to 150ºc
Line a 20cm round cake tin with baking paper, on the bottom and around the sides.
Combine butter, chocolate with 200 mls of water in a medium saucepan over medium heat and cook until melted together - set aside to cool slightly.
Meanwhile, mix the Caramel Top n Fill until it’s a smooth consistency. Add ¾ of the Top n Fill, brown sugar and vanilla, to the chocolate mix & stir well.
Add eggs and mix well.
Sift in flours whisking as you go to prevent any lumps. If you are after a good work out, you can whisk the mixture by hand in the saucepan until it’s combined and smooth, or alternatively you can use and electric mixer and beat for approximately one minute until it is smooth.
Pour into the lined cake tin and cook for 1hr and 20mins, or until a skewer inserted into the middle comes out with moist crumbs on it.
To decorate, you can use the remaining Caramel Top & Fill and spread all over the cake and decorate with Maltesers like I did. You could also decorate with a milk or white chocolate ganache.
This cake will keep wrapped and in an air tight container for 5 - 7 days - that is if you haven’t already eaten it all!