In a large bowl, add the flour and the yoghurt. Mix together, either with a spoon or you can use your hands, until a dough forms. I usually start with a spoon, tip it onto a clean surface, and then use my hands to bring it together. The dough will be a little sticky but still light. If it is too sticky, add a sprinkle more flour.
Once a dough has formed, split it into four and roll each into a ball. Using a clean finger, poke a hole in the middle of each ball and then swing the bagel around your finger like a hula-hoop to stretch it and make a bagel shape. Or you can roll each quarter of the dough into a sausage shape and then pinch the two ends together to form a circular ring.
Get a large pot of water on to boil and add the baking powder. Add your bagels in (you will probably need to do this one at a time, maybe two) and boil for 1-2 minutes. Remove from the water and set aside, laying each bagel on a tray lined with parchment paper.
Heat the oven to 180c. Beat the egg and then use a pastry brush to egg wash each bagel. Then sprinkle on your topping of choice. The egg wash helps this stick and helps them turn golden brown in the oven.
Bake for around 30 minutes, you want them golden brown and crisp on the outside, then remove from the oven. Nothing better than a warm fresh bagel!