Grease and line the base and sides of a 20cm square cake pan with baking paper.
Place the sweetened condensed milk and chocolate bits in a medium-sized saucepan over low heat. Cook, stirring, for 5 to 7 minutes or until melted and combined.
Pour half of the chocolate mixture into the prepared pan. Place a layer of Funpack KitKat chocolate on top. Pour over remaining chocolate mixture and smooth the surface. Arrange another layer of KitKat on top. Cover with plastic wrap and place in the fridge for 2 hours or until set.
Cup into squares to serve.
