The baking time depends by your oven. I baked the cake in different ovens and the time was always different so the best is to have a look already after 40 minutes and then decide for the additional time.
The cake is best if you let it stay in a cool place (no fridge) for one or two days in order to get all the taste.
Instead of walnuts you can take also other nuts. Also the almond meal could be walnut or hazelnut meal. But be aware the taste will be different.
You can serve this cake with jam or marmalade.