A while ago I wandered across this LJ post and noted it. I didn't try the recipe right off. On a recent visit to my folks I found that they had tried it and found workable, though the result was a bit rubbery. If you didn't take the link, here's the recipe:
5 MINUTE CHOCOLATE MUG CAKE
4 tablespoons flour
4 tablespoons sugar
2 tablespoons cocoa
3 tablespoons milk
3 tablespoons oil / 6 TBSP applesauce
3 tablespoons chocolate chips
A small splash of vanilla extract
Dash of salt
1 large coffee mug (microwave safe)
Add dry ingredients to mug, and mix well. Add the egg and mix thoroughly.
Pour in the milk and oil and mix well.
Add the chocolate chips (if using) and vanilla extract, and mix again.
Put your mug in the microwave and cook for 3 minutes at 1000 watts.
The cake will rise over the top of the mug, but don't be alarmed!
Allow to cool a little and top with whip[ped] cream or ice cream.
Or tip it out onto a plate if want to divide with another person...
EAT! (this can serve 2 if you want to feel slightly more virtuous).
This morning I tried it. It works. The result is slightly rubbery, but not badly so. Considering how little time it takes to make and how easy it is, that's not too bad a trade. I do wonder if changing something might help that a bit. I don't need it to be a 3 minute bake time, so a change there wouldn't be bad, though I would like to keep the microwave convenience: no preheating, relatively short baking time.
I did make a couple changes: I mixed things in a small mixing bowl and then poured the result in a Pyrex measuring cup that I had sprayed with oil to make extraction easier. This does easily serve two people without seeming insufficient unless you're feeling particularly gluttonous. I also cut the baking time short by about 15 seconds since I was using a 1100 Watt, rather than a 1000 Watt, microwave. Perhaps I still overbaked it?
I have seen suggestions, but have not tried them yet, for modifications. One is to add just a pinch of salt - something I forgot. I'm not sure what that will do. Another is to make a non-chocolate cake by substituting flour for the cocoa and adding or adjusting flavoring. Someone even suggestion using Bailey's (or similar) instead of milk. I suspect more alcohol would survive the short baking time than in regular oven baking. I also wonder if using softened butter rather than oil would help the texture or feel.
Also, yes, I know that 4 Tablespoons is 1/4 Cup, but in this case, especially if you use a coffee mug, pouring is just easier with the Tablespoon measure. And you won't need to clean the 1/4 cup measure if you don't use it.
Some versions call this the "Most Dangerous 5-Minute Chocolate Mug Cake" as it's only about 5 minutes from start to finish and thus chocolate is never more than 5 minutes away. It is tempting to make another and try some variation.