Chocolate and mashed potatoes may sound like a funny combination, but it’s not as strange as you think. Chocolate potato cake recipes have been around since the start of the 20th century, with one appearing in the classic cookbook “A New Book of Cookery” by Fannie Merritt Farmer. In the cookbook, Farmer instructs that you combine riced potatoes with flour, butter, milk, eggs, sugar, and grated chocolate, before baking it and covering it with a fudgey chocolate frosting.
The result is an ultra-moist cake, with a tender crumb and a mild yet rich flavor. Potatoes, like flour, have starch in them, and this starch helps to hold the cake together while keeping it soft and delightfully chewy. You can, of course, substitute the grated chocolate for cocoa powder, to achieve a deeper chocolate flavor and a dark-brown color throughout. If you go with grated chocolate, however, you’ll find that your crumb is lighter, and almost looks like a banana bread or a wheat flour loaf. Mashed potato is also a great choice for gluten-free cakes, as it performs much of the function that regular flour does. If you opt for this, try combining it with a small amount of rice flour and some ground almonds.