Place flour, baking powder, salt, and 1/4 cup cocoa powder (save the other half for the frosting) in a large bowl and whisk together. Believe it or not, there is absolutely no sugar–or any sweetener for that matter–added to the cake batter.
In a separate bowl, whisk together plant milk, vanilla, and apple sauce. I always purchase unsweetened applesauce, but you can make it homemade if desired. I've included instructions on how to make your own in the article above.
Next, pour the wet batter mixture into the flour mixture and whisk together well. Keep in mind that if you taste the batter, it won’t be great because there is no sweetener in it yet. That’s added in the fudge sauce coming up.
Pour the batter into a 4-6 quart crockpot or slow cooker and set it to medium heat. You will notice in my photos above that I lined my crockpot with white parchment paper that is usually used to prevent sticking. You don't need to do this. I only used the parchment paper for these photos because my crockpot is black and made it difficult to see the batter.
One addition I like to make at this point is to sprinkle 1-2 tablespoons of non-dairy chocolate chips over the top of the batter. This is of course optional.
Making the frosting
Mix the three ingredients for the fudge sauce--1/4 cup cocoa, hot water, and sugar. This is where the sweetness comes in and, believe it or not, the sugar in this simple sauce is enough to sweeten the entire cake. Make sure your water is very hot to dissolve the sugar.
Pour the frosting sauce into the crockpot over the cake batter. It will look very watery, but the sauce will thicken up into fudgy heaven!
Place slow-cooker lid on top and allow the cake to cook on medium for approximately 3 hours. Crockpot temperatures vary, so check after 2 hours to see how it’s coming along. You want it to be firm but still moist on the top.
For those with crockpots that don't have a medium setting, I've included other setting options and times in the article above.
When a spoon is used to cut into the top, the hot fudge sauce on the bottom will be ready to spoon over each serving.
Video
Notes
Detailed instructions, in-process photos, and my personal helpful tips can be found in the article above.Tips for making a crockpot lava cake
Make it gluten-free- This cake is not gluten-free, but this link to the Minimalist Baker will help adjust it for those that want to give it a try.
Increasing servings- The basic cake recipe serves about 8 people, so if you are making this for a crowd, I suggest making a double-batch.
Oven cooking option- If you would like to make this recipe in the oven, this article will help- Easy Vegan Hot Fudge Cake.