This thread is lacking cake stops. I'll start.
'The Steyning Tea Rooms' 32 High Street, Steyning, West Sussex BN44 3YE
01903 810064 - not too far from South Downs Way and good Food
Carats Cafe Basin Road South, Southwick, BN41 1WF 01273 430 924 - note from A259 you have to cross the lock near Nautilus Hse: 90 – 100 Albion Street Southwick
http://www.southdownsway-hikersrest.com/ - Sadlescombe Farm, SDW. Good reports from those that spend more time eating cake than on a bike, but not been there yet. Check opening times.
Ditchling Tea Rooms 6-8 West Street Hassocks, West Sussex BN6 8TS, United Kingdom 01273 842 708 (It is very much in Ditchling - opp the church)
Would be good to find others, whether on road or off. Pref your favourites, but also if you know of a few 'useful to know about' ones if people need them. If they are the sort of place that can consistently ruin toast, perhaps best not mentioned