We're a little late answering this question from Liz, but it's still a good one for the holiday season ahead!
I have discovered David Lieberman's Fresh Ginger Cake recipe on Epicurious and am looking forward to whipping it up for Thanksgiving. I would love to incorporate pumpkin into it somehow, as we are foregoing pumpkin pie this year.
I thought about replacing some of the oil with canned pumpkin, but wondered how that would affect the texture. Or is there some other ingredient i can replace with pumpkin? Or just add the puree in and add in a bit more flour and eggs? I am not a baking scientist here, but I know enough to know that I need to get some good advice before proceeding! Thanks!
Here's the recipe that Liz spotted:
• Fresh Ginger Cake from Epicurious
Whenever you want to fiddle with a recipe, start by separating the recipe into its basic components and looking at the dry ingredients, wet ingredients, and those that might fall in between. In this recipe, the essential dry ingredients are the flour and sugar. The wet ingredients are molasses, oil, water, and eggs. All the other ingredients are mostly there for flavor (or leavening, in the case of baking soda), but since they don't add extra volume, we can set them aside for the moment.
Next look at the ingredient you want to substitute into your recipe and determine which category it falls into. Canned pumpkin is a little tricky since it's liquidy, but also fairly solid and dense. This puts it in the "between" category.
Now it's all about keeping an equilibrium! We should add about a cup of puree to get a good pumpkin flavor, and then reduce the dry ingredients by a half cup and the wet ingredients by a half cup to compensate.
On the dry side, let's leave the sugar as it is (we want our cake to stay sweet, after all!) and try reducing the flour by a half cup.
On the wet side, we have some choices. The molasses are primarily there for flavor; the oil tenderizes and keeps the cake moist; the water is there to thin the batter out; and the eggs bind everything together while adding richness. In this recipe, the water and the molasses are the least essential to the structure of the cake, so try reducing each of those by a quarter cup.
All the other ingredients will stay the same - though if you're using spiced puree, you'll probably want to reduce those called for in the recipe.
Good luck! Please report back and let us know how the cake turns out!
Does anyone else have any good tips for doing recipe substitutions?