Fail Better - Sponge cake

Someone on my team got offered a permanent contract, which started on Monday. I thought it was something worth celebrating, and asked him what type of cake he likes. He said plain sponge.

I think eggs are my bane (see my failed soufflé attempt), as I tried making a sponge cake Tuesday morning to bring to work, and this is what happened:

(That isn't one sponge cake cut in half, but two "sponge" cakes". I ripped a chunk out to taste it.)

I couldn't bring such an abomination to the office, so I arrived empty-handed and said I would try again. He told me to Google "Wawrinka tattoo" and I was dubious at first, but he promised it would be something safe to look at on my work computer. It's a tattoo that tennis player Stanislas Wawrinka has on his forearm that says:

Ever Tried. Ever failed. No Matter. Try again. Fail again. Fail better.

I found a different recipe and Tuesday evening, I had this:

Both still flat like pancakes, and one was so burnt. I tried to rescue it by cutting the top off, but it was beyond help. Although, despite being horribly flat, the bits that weren't burnt were delicious. I guess that's failing better?

Once again, I arrived at the office empty-handed. He said to me, "You need to look at the tattoo again, don't you?"

So Wednesday night, determined to get it right this time, I tried another recipe and made this:

Much more rise this time, but it didn't taste as good as the second one. There was far too much cake, so I ended up slicing about half off each cake. I also thought it was a bit too plain, so I whipped up some cream, put in a layer of strawberry jam and dusted it with icing sugar.

The guy from work loved it, and ended up eating 3 slices for breakfast. This was all that was left by lunchtime, and he ended up polishing it off after lunch.

I now have 2 and a half sponge cakes in the freezer, but a much better technique for making sponge cake. I think my problem was that two of the recipes recommended using a stand mixer with a whisk attachment, and I don't have one of those. They whisked whole eggs, and I couldn't get the same effect with my electric beaters. The recipe that ended up working for me involved separating the eggs and beating the egg whites separately.

The recipes I used:

#1 https://www.donnahay.com.au/recipes/classic-sponge-cake-with-jam-and-cream
#2 https://www.gretchensbakery.com/vanilla-sponge-cake-recipe/
#3 https://www.howtocookthat.net/public_html/sponge-cake-recipe/