Step 1- Biscuit Base: Finely chop 200gm white soap noodles; add 40ml vegetable oil and 100ml water
Microwave 100% for 2 minutes, stir with a wooden spoon, and then at 60% power another 2 minutes.
Mix in 1 teaspoon cinnamon and 1 tablespoon wheatgerm.
Line an 8 inch cake tin with baking paper for easy removal later.
Spread the soap mixture into the base, leaving it rough on top.

Step 2 - Lemon Filling: Finely chop 400gm soap noodles; add 80ml vegetable oil and 200ml water.
Microwave 100% for 2 minutes, then 60% for 2 +2, stirring with a wooden spoon between each time.
Add the yellow dye to get the effect you want, less is best, you can always add more. 
Stir in essential oil, lemon would be the choice here.

Spread over the base, again leaving it rough on the surface.

Step 3 - Cut: As the soap cools you can cut it into pie shape wedges as in the picture. 
It is much simpler to cut carefully when it is still warm; remove when cold.

Step 4 - Piping: Mix 400gm finely chopped soap with 80ml vegetable oil and 200ml water, then microwave as in Step 2; stir in the essential oil.
Put this soap into a piping bag and pipe onto each slice separately.

VARIATIONS

Strawberry Flan: Steps 1 - 3 as above using red or pink colouring
step 4: use 100gm grated soap, mix with 20ml oil and 50ml water, adding red or pink again - mould in a tube about 5cm diameter (cardboard roll from plastic wrap etc), slice up and then carve into strawberry shapes as in the photo over page

Step 5: use the other 300gm grated soap with 60ml oil and 150ml water - use a knife to spread some of this mix over the front of the wedges, then add the strawberry pieces, and finish with the piping bag at the larger end of the wedge  

Plain Blocks: simply use step 2 and mould into clean milk containers, food tins with both ends removed, plumbers pipe etc, then slice.