Ooey-Gooey Chocolate is a finishing reagent that has the property of setting the Multicraft on a recipe to exactly 100%, as per the Blizzard UI. It seems that CS is not accounting for this.

Here's the recipe for Fated Fortune Cookie. With the Master Wildercloth Chef's Hat equipped, I have a multicraft of 4% on the recipe. (My rolling pin is enchanted with Resourcefulness, so no multicraft coming from there.)

Next, I add OGC to the recipe. Note that Multicraft is now 100%. CS recognizes the extra cost of the OGC in the Average Profit window, but not the multicraft of the recipe. Given that the AH sell price of the Fated Fortune Cookie is about 84g, the profit per craft should go way up, despite the OGC's 25g override cost.

Next, I remove the OGC and take off my chef's hat. Note that the multicraft is now zero:

Again, I add the OGC. Note that multicraft is again set to 100%.

One additional scenario: OGC does not appear to stack with Salad on the Side, the other finishing reagent that gives +multicraft, even though you can use both in one recipe.

Here's the FFC with just the Salad, which adds about 8% multicraft to my base 4% from the Chef's Hat:

Adding the OGC again just sets the multicraft to a flat 100%, ignoring the bonus from the Salad. However, the tooltip does show an internal number over 100%. I didn't test whether the multicraft actually goes over 100% internally and just the display is capped at 100%. Given the one-a-day cooldown on OGC, I'm not sure we can get enough data for a meaningful statistical analysis.

One last note: Adding the OGC with a zero base multicraft has the tooltip showing +1100 multicraft for the same 100% rate.

Testing my single available combine with the OGC, it produced the expected two fortune cookies:

-> 12.2.0