Creamy Brown Custard Donuts Recipe

DONUT 300g Bread Flour 3g Salt 40g Sugar 4g Instant Yeast 200ml Milk (tepid) 30g Softened Butter (room temp) Caster Sugar to coat BROWN CUSTARD 2 Egg Yolks 50g White Sugar 50g Brown Sugar 250ml Heavy Cream 20g Corn Starch OIL 1.4L Canola Oil to fry @ 180°C/360°F