Beat all ingredients, except wafers, in a large bowl and mix until creamy.
Lay a long piece of plastic wrap or foil (twice the length of the wafers) over your work surface and lay one of the wafers in the centre, waffled side up.
Spread with a quarter (250 g) of the chocolate mixture all the way to the edges. Lay another wafer over the top and repeat the process with the final sheet of wafer. Do not spread chocolate over the top layer.
Gather the plastic wrap or foil from both sides and wrap the wafer cake well before refrigerating for a few hours or overnight.
Cut into diamond shapes before serving.
Divide the chocolate filling into four (250 g) before using. This ensures the layers will be evenly filled.