1½ cups superfine almond flour, ½ teaspoon baking soda
Pour the batter into the prepared pan. Bake until the cake is puffed and a toothpick inserted in the center comes out clean, about 20 minutes.
Cool the cake in the pan on a cooling rack for 20 minutes, then cut it into nine squares and serve.
Video
Notes
Sweetness is a personal preference. Use these amounts as a guide and adjust to taste.
Occasionally, baking soda can cause a reaction in baked goods that results in an ammonia smell. If you're concerned about it happening, use ½ tablespoon of fresh, non-expired baking powder (gluten-free if needed) instead of baking soda.
You can use a granulated sweetener instead of stevia. If the batter seems too thick, add an extra tablespoon of milk.
I don't recommend using ginger powder. The flavor will suffer. If you must, you can use ¼ teaspoon, but I highly recommend waiting with this recipe until you have fresh ginger.
This might be somewhat unusual, but I like to add a tablespoon of cocoa powder. It gives the cake a deeper color and an additional layer of rich flavor. This is useful because I don't use brown sugar or molasses.
If using baking soda, it's best to use natural cacao powder (not treated with alkali). Its acidity will help activate the baking soda, ensuring a fluffy cake. If using baking powder, it's fine to use cocoa powder treated with alkali.
Once completely cool, you can wrap the cake in cling wrap, then in a layer of foil, and store it in the fridge. It keeps well for about 5 days. You can also wrap and freeze it, or freeze individual slices in freezer bags.