Synthetic vanillin is fine for baked/heated goods because the differentiators present in actual vanilla extract are overwhelmingly volatile compounds that evapo

Synthetic vanillin is fine for baked/heated goods because the differentiators present in actual vanilla extract are overwhelmingly volatile compounds that evaporate in the first few minutes of baking. By the time you pull the goods out of the oven, the result is nearly chemically indistinguishable. This is why many no-bake custard recipes specify that the vanilla should be added only as one of the last few steps, after all heating is completed.