For 5 minutes, microwave the sweet potato wrapped in a wet paper towel to bake the cake. Switch sides and microwave 5 more minutes. Flip and microwave another 3-5 minutes if sweet potato is hard.
Bake or boil sweet potatoes instead of microwaving. Cool the sweet potato completely. This helps peel potatoes and stop cake batter eggs from cooking.
Remove sweet potato skin. Mash sweet potato until creamy and measure one cup. Turn on the oven to 350°F and line a 9-inch square or round cake pan with parchment. Spray the pan with cooking spray instead of parchment.
Mix mashed sweet potato, almond butter, eggs, pure maple syrup, vanilla extract, and vinegar in a large bowl. Wet ingredients should be thick and sticky. Almond butter softens and mixes in 20–30 seconds in the microwave or cool.
Add cocoa powder, baking soda, ground cinnamon, and sea salt to wet ingredients for a thick cake batter. Add 1 cup chocolate chips for more chocolatey goodness.
Pour cake batter into pan evenly.The cake should test clean after 23–28 minutes on the centre rack of the preheated oven. Make the optional ganache frosting a few minutes before baking.
In a bowl, microwave chocolate chips, full-fat coconut milk, and coconut oil (or butter) for 20 seconds at a time, stirring well, until fully melted (about 60 seconds).
Prepare and spread ganache on warm cake. Put buttercream and chocolate frosting on the cake at room temperature or colder.
Cake with warm ganache. Wait until cake is room temperature to slice and serve. Refrigerating the cake sets and cools the ganache faster.Share and enjoy cake!