Lately, I’ve seen a lot of microwave cake recipes going around, sporting names like 5-minute cake, 3-minute cake, and even a 1-minute muffin! It takes me longer than 5 minutes to make all of them. However, they’re easily adaptable to low carb. And the resulting cake is small enough that you can eat all if it with minimal guilt (though I consider them to be 2-serving cakes).
These recipes are incredibly friendly to substitution. For the almond flour, you can substitute regular flour or another nut flour or, I’m told, even protein powder or flaxseed. You can substitute coconut oil or another fat for the butter. You can use real sugar or stevia instead of Splenda. You can try different flavors. (I’m working on German Chocolate Cake next.)
I’ve been playing with the basic recipes and have come up with one of my own. I’ve been a bit irritated by how many utensils I have to use to make these cakes, so I’ve streamlined that some, too.
Microwave Low-Carb Orange Cream Cake
Ingredients:
3 tablespoons butter
4 tablespoons almond flour
4 tablespoons Splenda
1 egg
3 tablespoons sour cream
1/4 teaspoon baking powder
1/2 teaspoon orange extract
Hardware:
Cutting board (to cut butter and keep counter clean)
A 2-cup Pyrex measuring cup (I am told a large coffee mug also works well)
Knife (to cut butter, aid in transferring sour cream from spoon to Pyrex, and cut the cake in half)
Fork (for mixing)
1/4 teaspoon and 1 tablespoon measuring spoons
Plastic wrap
Microwave

Directions:
1. Cut 3 tablespoons of butter from the stick of butter.
2. Melt butter in Pyrex container. The goal is to heat it enough to melt it completely but to allow it to cool some before the egg is added, so it doesn’t cook the egg on contact.
3. Add almond flour, Splenda, egg, sour cream, baking powder, and orange extract. Use the 1/4 teaspoon measuring spoon twice to get enough orange extract, rather than getting another spoon dirty.
4. Mix well. If you don’t mix it well enough, you will have streaks of egg in your cake. It should look like the picture below. Only not as blurry.

5. Cover with plastic wrap and microwave on high for 3 minutes. Remove hot Pyrex container from microwave; remove plastic wrap, taking care not to steam your hand; and let cake stand for 1 minute before upending onto a plate.

6. Cut in half and serve.
As written, each serving contains 307 calories, 29.1 g fat, 7 g total carbohydrate, 1.5 g dietary fiber, 6.0 g protein.

I plan to try this cake with stevia soon, as I prefer it to Splenda. As I said before, I’m working on a German chocolate version, with red velvet on the distant horizon (though I’ll likely leave out the “red”). If you try this or a similar recipe, I’d love to know about your experience!
12/14/2008 Update: Instructions for making your own almond flour are here, along with a yummy-looking cookie recipe, although I haven’t tried it.
3/23/2009 Update: The majority of my spam comments are appended to this post, so I’m going to close this post to comments.