I know this is a super old post, but thought I'd share a recipe for anyone else who might be searching. I usually bake dairy/egg/nut-free due to family allergies, with good success. It certainly is a challenge to add gluten to the list of allergens, though! Having two different friends' kids with these allergies PLUS allergies to soy and wheat, I couldn't resist the challenge to bless them. This recipe has gotten the thumbs up from both kids, as well as the mom (who has no allergies, but has tasted many allergy-free foods). I bake as a hobby, and am not a professional baker by any means. But hopefully this recipe can help someone (since I probably couldn't contribute much knowledge otherwise)!
Dairy/Gluten/Egg/Soy-free Chocolate Cake
Yield: Makes one 9" round cake, or about 14 cupcakes.
1.5 cups of GF flour (I make my own combination by weight: 84g brown rice flour + 63g white rice flour + 63g potato starch)
1 tsp xanthan gum
1 cup sugar
1/4 cup (or 4 Tbsp) unsweetened cocoa powder
2 tsp baking soda
1/2 tsp salt
5 Tbsp canola oil
1 Tbsp vinegar
1 tsp vanilla extract
1 cup water
1. Preheat oven to 350 degrees F. If making cupcakes, I recommend using foil liners, otherwise the paper ones get pretty greasy.
2. Whisk together dry ingredients (first 6 ingredients listed).
3. Add oil, vinegar and vanilla. Mix to thoroughly moisten. Mixture will be crumbly.
4. Add water and mix to combine/incorporate.
5. Bake in prepared 9" round pan for about 35 minutes, when center looks set (not so shiny) and springs back at slight touch (or at least doesn't sink). I didn't feel that the toothpick test was quite as reliable, since it may come out clean but still be too moist/pasty in the middle.
Cake is still more dense, but is decent. I haven't played around with other flours to see if I could get a better crumb. If I do one day, I'll let you know!
Incidentally, many people with soy allergies can have soybean oil and soy lecithin. It is helpful to know if this is the case (best to check with their doctor of course). But it's a huge game changer if they can! My friend thought her daughter had to avoid all soybean oil, and did that painfully for years until I questioned her about it. She checked with the doc, and they got the thumbs up on soybean oil & soy lecithin! So... I also bake with Fleischmann's UNSALTED margarine sticks without any issue for both my friends' children... AND, at the risk of sounding sacrelig on a cake forum, this also opens the door for using Pillsbury tub frosting (most flavors are okay, even the "milk chocolate" one)!