3 ingredients
Boiled sweet potato(still hot or warm when combining with the flour) heat up the sweet potato if you are using left over. All purpose flour 1:1. I used Jovial organic einkorn ancient flour. Sea salt, a pinch or two.
Crunch in. So good. Even the walnuts. The beans are done not chips like but crunchy and tasty nontheless.
The thick ones are chewy in the center and crunchy outside and I love that. Otherwise put it back for 5 more minutes removing the thin sliced sweet potato chips because they are crunchy and done already. 
I used simple Jiffy cake mix. Following the instruction adding an egg and my friend advice me to always use milk instead of water. I used cashew milk to reduce my lactate intake. Mix well to make the cake batter. Add greek yogurt or pudding mix if you wish a creamier, densed and softer moist cake unless your prefer light and fluffy otherwise.
Fold the frothy egg white we made earlier into the batter gently. 

I left lumps so I could have that soft and airy, fluffy, texture of my cake when it's baked.
In another bowl combine egg yolks (I used 5, you can use more if you'd like), condensed milk and vanilla extract. In the Filipino way, they add granulated sugar. The condensed milk is sweet enough, so I did not add sugar anymore. I added a cup of regular milk or skim milk or cashew milk.
Mix gently. Sift if you want a very smooth flan/custard. I left it as it is.
Pour the egg yolk mixture to the sugared pan earlier.
Then pour in the egg white meringue and cake batter mixture.
In a bigger pan add water, then put the mixture on top. Some use a baking rack.
Bake for 50-60 minutes at 350 degrees F 
My timer went off at 50 minute mark and my friend always tell me to poke the cake to see if it is ready. I use a chopstick.
Voila! Bon appètit.