First wash the poppy seeds in water to remove any dirt they may have picked up in processing. This is not an entirely necessary step but they do acquire dirt and it also helps to soften the seeds.
Put the washed poppy seeds aside. Cream the butter and the sugar in a mixing bowl with paddle attachment. Once the mixture is light and fluffy slowly add the eggs one by one until incorporated into the mixture. Add vanilla essence.
Fold in the flour, baking powder and poppy seed
Spoon mixture into a loaf tin and cook at 180C approx 1hr 30mins.