The idea for this dessert came about because I wanted to create something similar to a Chess Pie, a Southern pie that is baked with a buttermilk custard, but I did not want to do something too predictable. So I looked into different kinds of pies that were similar to Chess Pie, and came across Buko Pie. Buko Pie is a Filipino dessert, quite similar to Chess Pie, just baked with a young coconut flan-type of filling with shreds of young coconut running through it. Just baking a Filipino dessert reminds me of my coworker, Beth, who actually introduced me to mirror glaze cakes in the first place! So this one goes out to you, Beth! Since I was already going the Filipino route anyways, I figured, why not bring ube into this and infuse that into the crust. After Googling results for ube buko pies, I did not see any that had a vibrant purple crust, so I knew that it was not something done too often, so why not try it out and put a purple buko pie on the internet? For my pie, I
could not make enough crust, so I could not do a top crust, whoops really wanted to showcase that custard filling with the strands of young coconut running through the flan, so I opted to do a cute little ring of purple flowers around the edges instead of a proper crust, which is seen in more typical buko pies. I mean, I’m not typical nor am I traditional, so I guess those aspects of basically anything I make gets thrown out the window anyways, so don’t be so surprised about that.
For the crust, I had to be extremely careful. Most ube desserts on the internet was dyed using artificial coloring to get that vibrant purple color, but I did not want to do that for mine. So I decided to combine all of the different methods I knew for guaranteeing 100% that my crust would turn out purple, and basically put them into one recipe to guarantee that my pie crust does not turn out blue, puke-green, or anything other than deep, vibrant purple. I combined frozen grated ube with Okinawan sweet potatoes, which I know right away will make anything deep purple – so in this case, I flavored the crust with the ube, but dyed it with the sweet potato. I also used baking powder which will not discolor the potatoes, pitaya powder, which turns things pink, to offset any green coloring that may happen in baking, and Japanese purple sweet potato powder to really reinforce the purple color in the crust. I also set the baking temp to much, much lower so that the potatoes would not brown too much and discolor from the oven, and I did not add any sugar into the crust to further guarantee a lack of browning. Additionally, to make sure that the ube and potatoes were the focus for my crust, I made it entirely gluten-free. The filling, which is my young coconut leche flan, is made using condensed milk, plenty of eggs, young coconut water, young coconut flesh, and cornstarch.
For the crust:
1/2 cup purple sweet potato puree; I poke holes in then microwaved the potato for 5 minutes
1/2 cup pureed ube; I blanched and then pureed frozen ube
6 tablespoons unsalted butter
3/4 teaspoons baking powder
2 teaspoons xanthan gum
3/4 cups tapioca or potato starch + more for dusting
2 tablespoons purple sweet potato powder
1 teaspoon pitaya powder
Combine ingredients and knead into a fine dough. Dust a surface with starch. Roll out to about 1/8th an inch thickness and place into a lined pie tin. Trim off the excess as you will be using that for the top portion. Weigh then bake at 300 degrees F for 40 minutes. With the remainder of the crust, roll out to 1/8th inch thickness, then cut out desired shapes. Place around the edge of the crust so that when you pour in the filling, you can just bake off the designs with the filling.
For the coconut leche flan filling:
1 egg yolk
14 oz sweetened condensed milk
juice and flesh of 1 young coconut
1/3 cup cornstarch
a pinch of salt
In a pot, reduce down the coconut juice with the cornstarch until the mixture is reduced by about half. Take off heat, then mix in the condensed milk. Temper with eggs and then season with salt and fold in thinly julienned slices of young coconut flesh. Pour into the already cooked pie crust and then bake at 300 degrees F for 50 minutes. The flan should have a slight wobble to it still when you take it out of the oven, which is an indicator that it is properly set.
Should you have excess filling, just pour in enough to fill the pie tin and then you can bake off the rest separately, or make mini pies using the remaining filling.