Set fanforced oven to 175°C.
Approximately 450ml of plain flour
200g room temperature butter
Vanilla essence/extract/paste to taste
2 table spoons cocoa
Cream the butter and sugar until fluffy, add the vanilla extract/essence/paste then add the flour (depending on how it all comes together, you might need a bit more flour).
Divide the dough into two equal sized portions. Add cocoa to one of the halves.
Divide each half in half, so you have four equal sized portions. Roll these into sausages/snakes and arrange them so they’re in a checker-board pattern (from the side).
Press it together gently into a square-ish shape and refrigerate for a while until they’re easy to slice into 3-4mm thick slices.
Bake for approximately 10 minutes.
As an alternative, after adding the cocoa to half the mixture, roll each colour into equal sized square sheets and layer them on top of one-another. Roll up, refrigerate, slice, and bake.