Why does my cupcake texture end up with a watery-scrambled egg texture, with a sulfurish smell I've gotten a batter recipe, but I fear that it might have something wrong with it.


Mix together 250 grams butter and 200 grams sugar
Add 4 eggs, one at a time
Add 2 tbs baking soda, 2 tbs Sodium bicarbonate, 300 grams flour
Stir; add food coloring and extract flavor, to taste 


I did add some titanium dioxyde to make the butter whiter before adding the coloring. Then, I added a few drops of red, and a few drops of strawberry taste for the fun of it. 

They were baked at 180c-(350F) for about 12 minutes. When I opened the oven, the front row of cupcakes fell together. I then closed it, and let them bake for another 5-7 minutes

I have tried it twice now: some of the cupcakes fell, those that didn't ended up smelling funky, and the texture resembled finely scrambled eggs.

Are there some ingredients that don't really mix together well? 

I did taste the batter, and the batter did taste delicious; that's why I wonder why the cupcakes won't cook correctly and be tasty.
I wonder if perhaps you've made a typo in regards to the proportions of this formulation. Try to source a reliable and tested recipe and compare ingredient components to modify what you're trying to achieve.

Please note, baking soda and sodium bicarbonate are identical ingredients.
Also, it is good advice to not open the oven until the cake(s) are close to completion.

I'd love to inquire as to the reason you are adding titanium dioxide to butter/trying to "whiten" it. 

As for the off-aroma, ensure the eggs you use are fresh.

I hope this is more PC of an answer.