Hi Brigitte,
OK: "Yummy" that's a comment.
But why only
half a cup of coffee?
More seriously; I think you might like to try a little experiment, take a biscuit to a table lamp and alter the angle of light across the surface and photograph it at several angles. We don't need to see all of them, but on a textured surface like that, with the writing, see what works and what doesn't at enhancing the contrast and texture.
I suggest a table lamp as it will give a bit more directional light than a window.
Cheers,