I used a white cake recipe using egg whites. it is from baking by cook's illustrated. It calls for egg whites, butter, and milk basically. I used powdered egg whites and the only changes I made was substituting half of the cake flour with regular flour(because I ran out of cake flour!) and using powder milk (I was out of milk too!). I baked it as per the recipe for 25 mints at 350. it wasn't done after 25 so I baked it for 30 minutes. still the cake looked kind of dense and not completely baked and heavy and it smelled like eggs and I could taste the eggs. The edges were pulling away from the pan so I took it out of the oven. I don't know what went wrong. Could anyone let me know what could have happened? why does it smell like eggs? I also used about 1.5 tbsp of vanilla. Help!!

I am not surprised that this did not work for you. You made so many changes that it is not the same recipe any more. I have that book, so I'll take a look. But CI has those recipes so fine tuned that one substitution and you are changing what they said you would get.

The cake flour is used for a reason, so doing a half and half thing will throw it off. You used powdered milk instead of whole milk, that will throw it off. And you used powdered eggs. Just the fact that you had to bake it longer means your science project when astray. Yes, baking is science, as much as everybody else doesn't like to admit it. I have seen that said enough by trained professionals to not believe it.

You probably measured everything out instead of weighing, that throws it off. Because you can measure the ingredients over and over and not weighing and you will get different amounts every single time. The way you scooped out the powdered eggs and milk can make a difference too. Too heavy or too light of a hand and you will not get the exact amount needed.

You also needed to know just how much water to add for all the dry ingredients to get it right. I bet you adding what was needed for both the powdered eggs and the dry milk was probably too much given the cake was dense.

I have no idea where you live, so maybe getting this stuff fresh is something you can't do. But I would try the recipe again with the exact ingredients needed.

And lastly a white cake will rely on the eggs whites to add in raising. I have never used powdered egg whites, but I am thinking something is missing in the dehydration process that is needed for the cake.

But with so many changes to the ingredients you made, there is no telling where the one thing is that went wrong. I think it was all of the above.