Mix flour, sugar, yam, active dry yeast
Pour in 150 ml water (just slightly warm, not even lukewarm), mix
Knead in 3/4 - 1 c flour
Cover with cling wrap and let stand in warm area until doubled in size
Punch down, cover and let rest again for 20 mins
Heat oil on medium heat
While oil is heating, divide dough into 6-7 balls, shaped into donuts
Fry until golden brown, turning once
Spread vegan margarine/butter on warm donuts
Dip donuts on your fav. Sprinkles (Or spread vegan Nutella/ganache)