Preheat the oven to 350° Fahrenheit, and grease an 8×8 inch cake pan with a little bit of melted butter or spray oil.

Combine the non-dairy milk, vinegar, and vanilla extract together and in a small mixing bowl, set aside to curdle.

In a large mixing bowl, combine the flour, sugar, cornstarch, baking soda, baking powder, and salt.

To the bowl, add in the oil and vegetable shortening. Using an electric hand mixer to work the shortening into the dry ingredients. Continue to do this until you get a crumbly texture.

Once you get a crumbly texture, add in half of the milk mixture and mix until you get a smooth batter. Add in the rest of the milk mixture and continue to mix until it is well combined. Do not overmix, small clumps are okay. Pour the cake batter into the 8×8 pan, and tap the pan onto a work surface to release any bubbles.

Bake for 20-25 minutes. Insert a toothpick and if it comes out clean, then it is done. Allow the cake to cool fully in the pan before adding the custard.

In a small bowl, combine the water and cornstarch. Mix until smooth and dissolved. Set aside.

In a large bowl, combine the coconut milk, soymilk, vanilla extract, granulated sugar, and cornstarch slurry. Whisk until fully combined, and the sugar is dissolved.

Next, melt the butter in a large saucepan, over medium heat. Then add in the custard mixture, and cook until it starts to thicken. Stirring constantly. It’ll take about 5-8 minutes.

Once it is thick, turn off the heat and carefully pour the custard over the cake. Sprinkle cinnamon over top, and allow it to fully cool to room temperature. Place the cake in the fridge to allow the custard to completely set, about 4 hours, or overnight. Serve and enjoy!