Grease and flour a large cake tin. In a large bowl, mix together the sugars and the butter, until light and fluffy.
Add vanilla, then eggs, one at a time. Beat well after each addition.
In a second bowl, mix the flour with the baking powder. Add half to the egg-butter-sugar mixture, and mix.
Add the milk and mix.
Add the rest of the flour, and mix until thoroughly combined. Pour into prepared pan.
Bake for just over an hour (check after an hour with a skewer dipped in the middle - if it comes out clean, your cake is ready). I baked mine in two thinner tins, but it still took about an hour.
Let the cake cool for 10 minutes before upturning on a wire rack and leave to cool completely.
For the frosting: mix the butter, cream cheese, and vanilla together. Add icing sugar mixture and 1/4 maple syrup, and stir until thoroughly combined. If you want a more pronounced maple flavour (I did), add up to 1/2 cup.