Magic Custard Cake

IngredientsFor the custard base:1 cup full-fat coconut milk (room temperature)1 cup unsweetened almond milk1/3 cup coconut flour1/4 cup almond flour1/3 cup erythritol or allulose (adjust to taste)2 tbsp tapioca starch (optional for better texture)1 tbsp ground flaxseed + 3 tbsp water (let sit for 5 mins = flax egg)1/4 tsp turmeric (for colour, optional)1/2 tsp vanilla extractPinch of saltFor the whipped layer:1/2 cup aquafaba (chickpea brine)1/4 tsp cream of tartar2 tbsp erythritol (or sweetener of choice)Instructions