I used her technique, but I didn't make the large "C" shapes like she did. Instead I did slighter smaller "C" shapes with the batter and some straight lines. I did two layers of these too not one. I did use a box cake for test purposes, and I used squeeze bottles for the two different chocolate colors. I found to have more control over placing the batter, but I think I'm going to try the pastry bags next time cutting a small hole at the tip. There was batter left inside the squeeze bottles that couldn't be pushed down like you can with pastry bags. For the darker chocolate I added cocoa powder to yellow cake batter and brown gel paste to get a darker color, the lighter brown I just scooped some of the darker chocolate into another bowl with more of yellow cake batter. I did have to add just a bit of the brown gel paste to get a better color. I'm sure you could just use all gel paste to get the colors you want instead of adding cocoa. I found you couldn't taste the cocoa so it makes no difference in the flavor element. I was thinking of trying it with brownie batter wondering if that would add more of a chocolate flavor to the cake. Sorry I didn't take pictures while I was doing this...wasn't thinking.
I did bake this cake late at night and didn't wait for it to cool all the way before cutting becaus I was so excited to see the results! It was very soft so the cuts aren't very clean....should have stuck it in the freezer for a few minutes. Anyway, all in all I really like the Crumb Boss's technique. It's less time consuming and the results are good.
I did try another technique, but it didn't work. With the two different chocolate colors I made a dot with the lighter brown and then using the darker chocolate I traced a circle around the dot. I made lots of them, added yellow batter on top, then did another layer of the dots and added yellow batter on top. It didn't give the prominent look of leopard print at all, but now I'm wondering if I had made the dots more of a longer oval shape.....hmmm, might have to experiment again. Anyway, give it a shot. Use a box cake mix so you're not wasting time and ingredients.