Here's the recipe for my Halloween Pinwheel Cookies in process.
Part 1 of 2: the dough-making phase. Except for a few flavor- and color-specific tweaks, the ingredients for each layer are the same.
The process is also the same. (Note: You will have to make each layer individually.) Cream together the butter and white sugar. Combine the wet ingredients and add to the creamed creamables. Grind the oatmeal. Combine the dry ingredients, add to the combined creamables and wet ingredients, and mix to combine.
Vanilla Layer: vanilla, finely ground Nilla Wafer cookies, and yellow food coloring.
Orange Layer: orange extract and red and yellow food coloring.
Chocolate Layer: cocoa powder and black food coloring.
See Picturing Halloween Pinwheel Cookies II for the assembly phase.