Preheat the oven to 180 degrees C. Grease a 23cm round cake tin.
In a medium bowl mix together the butter, sugar and almond essence until light and fluffy using an electric mixer. Blend in the egg. Combine the flour and baking powder; stir into the mixture using a sturdy spoon until dough forms a ball. Press the dough into the prepared pan.
Bake for 30 to 40 minutes in the preheated oven until the top is light golden brown. When cool slice into wedges to serve.