Lay out 4 slices of bread and butter one side. Sprinkle half of the two chocolates over buttered side of bread and top with mixed berries. Sprinkle remaining chocolate over berries. Butter remaining bread slices and press buttered side onto chocolate.
Whisk eggs, milk and spices. Heat a griddle on medium and grease lightly. Dip montecristo lightly into egg mixture and griddle until golden brown. Flip carefully and griddle until brown and chocolate is melted. Slice in half on an angle and dust with icing sugar. Serve immediately.