- Preheat oven to 160C.
- Cream the butter, sugar and orange zest in a bowl until light and fluffy.
- Beat in the eggs one by one.
- Sieve the flour and baking powder together and fold into the mixture.
- Combine the orange juice, yoghurt (or buttermilk) and poppy seeds and stir into the mix.
- Grease and flour an 8 inch round tin or two 2lb loaf tins, or use paper liners.
- Turn mix into tin and bake in centre of the oven for 40 minutes.