Pre-heat the oven to 170°C and line and grease a 20cm loose-based round cake tin.
Add the butter and sugar to a large mixing bowl and use a hand mixer to mix together. When the butter and sugar mixture has a creamy texture add the eggs and the lemon juice and continue mixing until smooth.
Sieve the flour and baking powder into the mixture and then add the lemon zest and poppy seeds and gently fold together until well mixed.
Spoon the mixture into the cake tin and smooth it down until level, bake for 40 minutes or until the centre feels springy.
When the cake is ready, remove the tin from the oven to a board, then straight away mix together the syrup ingredients.
Next stab the cake all over with a skewer and spoon the syrup evenly over the hot cake. Mix the rounded teaspoon of golden granulated sugar and the poppy sees together and finally sprinkle on the top of the cake.
After that the cake needs to cool in its tin before it can be removed and stored in an airtight container.