1. Preheat the over to 180C/350F/Gas Mark 4 - Reduce to 160C/330F and Gask Mark 3 if using a fan assisted oven.
2. Grease and line an 10in baking tin.
3. In the bowl of an electric food mixer break the eggs, add the butter, sugar, flour and baking powder.
4. Mix everything together until well combined and you have a smooth, creamy, 'dropping' consistency, that should fall off a spoon easily. NB: Be careful not to over-mix.
5. Spoon the mixture into the baking tin,smooth the top of the cake, and place in the middle of the oven and bake for 30 minutes. Under no circumstances should you open the door whilst the cake is cooking.
6. The cake will be finished when it is golden-brown and coming away from the edge of the baking tin. You will know if it is done by gently pressing the top and it is springy to the touch.
7. Remove from the oven and set aside to cool in its tin for 5 minutes before taking it out and placing on a wire rack.