Before making your cake, be sure to line the tin properly and set the oven to 170 degrees celcius. If you do not line your tin properly, you will find your cake difficult to release once it has cooled.
Cream your butter for a few minutes - this is important as it softens the butter - add your sugar and beat well together until it is a nice fluffy mixture.
Add your eggs one at a time, you can add a little of the flour if it looks like it might curdle.
Then add the vanilla, and all of the rest of the dry ingredients (flour, baking powder, salt) and mix well. Once your ingredients are thoroughly mixed they should resemble a thick drop consistency.
Transfer to the appropriate sized tin and bake in your oven for the stated time.
When your cake has finished cooking, remove it from the oven and leave it on the side, in it's tin until it is completely cool.
Cream your butter for a good 5 minutes until it has turned white.
Then add the icing sugar and beat well until it is light and fluffy, add the vanilla and mix in well.