These biscuits are two layer of cookie dough, one of them chocolate, rolled and sliced into biscuits. To make two same sized, even sheets of cookie dough, I use the wax paper envelope trick, rolling the dough between folded wax paper to create a rectangular even shape.
300 gms Cake Flour
1 Large Egg
200 gms Butter
150 gms Sugar
16 gms Coco Powder
1 1/2 Tablespoon Water
1. Cut the butter into pieces, and put into a mixture. Blend till soft.
2. Add the flour, sugar, egg and mix, add the water a little at a time, while mixing to form a solid dough.
3. Don't over mix the dough, you just want it evenly mixed, if you over work the dough, the finished biscuits will be hard.
4. Split the mix into two equal portions, take one half out, and leave one half in the mixer.
5. Add the coco-powder to the mixer half and mix just until the coco powder is spread through the dough.
6. Take a piece of wax paper (about 12 inches by 24 inches, 30cms x 60 cms), fold it in half along the longest side, then fold over the edges 2 inches (5cms) on each open edge to form an envelope as shown below. Make up 4 of these envelopes, you will need two for chocolate dough and two for regular dough. The size needs to be correct for the quantities of the ingredients - it will give you the correct thickness dough.
7. Cut the chocolate dough in half, and place half inside the envelope, folding the edges back.
8. Turn the envelope so the folds face downwards and roll the mixture to the edges and corners and make it flat and even.
9. Cut the white dough in half, place half inside a different wax paper envelope. Fold the edges of this one back, place the envelope fold-side-down and roll this one, also to be even and rectangular.
10. When you open the envelope, peel off the paper from one side, now close it again, flip the envelope over and peel it off the other side. Do this for both white and chocolate doughs.
11. Open the envelopes, lay the chocolate dough onto the white dough, if you life it with the wax paper it is easier. At this point you should have a layer of wax paper at the bottom, then a layer of white cookie dough, then a layer of chocolate cookie dough.
12. Now it needs to be rolled like a swiss roll. Lift the edge of the wax paper and roll the dough. As you do, peel back the wax paper. (You don't want the wax paper in the roll!).
13. Once you've got a sausage of dough, wrap it in the wax paper, twists the ends to form a wax-paper wrapped sausage and place them in the freezer for 1 hour. This is to make it hard enough to slice.
14. Cut the biscuits into 1 cms thick cross sections (1/3rd of an inch), place on a greased baking sheet (or better still a non-stick silicone baking sheet) and bake in the middle of a medium oven, at 180 degrees Celsius for 12-15 minutes.