Place the yeast, sugar and warm water in a bowl and stir until both the yeast and sugar have dissolved. Cover with cling film and leave in a warm spot for 15 minutes.
After 15 minutes, sift in the flour, baking powder and salt, pour in the milk and whisk to combine.
Once there are no lumps, cover it with cling film and place in a warm spot for around 35-40 minutes until bubbly.
Grease a frying pan with a little oil and heat over low heat. Lightly grease a 7-8cm diameter egg/crumpet ring and place on the pan. Spoon batter into the ring so it comes halfway up the sides and fry for around 5 minutes until the tops look dry.
Take the ring off, then flip over and cook for 1-2 mins until golden and firm. Repeat with the remaining batter.