I do not actually have a recipe,
@John Brunner . I do simple stuff, and this fiber cake is no exception. I start with a cheap cake mix (any flavor), and add foods with fiber, depending on what I have on hand each time.
I add seeds like chia, pumpkin, sunflower, or sesame, and flax seed that has been ground up. I add psyllium husks, acacia powder, or almond meal.
I add whatever fruits I have, like apple, banana, berries, or raisins.
Sometimes, I soak lentils overnight and then run them through the blender along with eggs, yogurt, kefir, or just plain water or milk. Or I add oatmeal or muesli.
The lentils are perfect with chocolate cake, and once they are baked, you do not even taste them. I soak about a cupful and then rinse them and blend .
You can also add canned beans, instead of lentils. I have even added blended spinach to the chocolate cake and you can’t tell it is there.
With chocolate cake, I add chocolate chips. In yellow cake, I add more fruit and raisins or cranberries. Everything depends on what I have handy, so I do not put all of this in every time, I just make sure that I add fiber foods to the mix. This should about double the size of cake, so I bake it in 2 cake pans for about 50 minutes at 350-375.
The basic idea is just to have a dessert that you can enjoy, or have for breakfast, and it have healthy foods and fiber in it. Just experiment with adding a little oatmeal to the cake mix first, like a cup or so, and then you can try other foods that sound good.
I forgot to mention vegetables, but carrots, squash, or sweet potatoes are all great to add in with yellow cake mixes, too. I do add a large spoonful of baking powder, because what comes in the cake mix is not enough by the time you have added al of the extras in.