Preheat the oven to 180°C (356°F).
Whip the butter and sugar together until creamy.
Add eggs one at a time, mixing well after each addition.
Sift together the flour, baking powder, and salt. Add to the mixture and combine.
Add lemon juice and lemon zest, mixing thoroughly.
Transfer the batter to a pound cake pan.
Bake in the oven for 40-45 minutes.
Let the cake cool completely before removing from the pan.