There are two nice cafés just to the south of Oundle; Kingfisher Café and Boxwood Café. Kingfisher is in the Barnwell Country Park, while Boxwood is behind the Barn Garden Centre one Km further south. Both have nice outdoor and indoor spaces.
Kingfisher has a lovely terrace overlooking a small lake and is usually a family favourite. Find out about it here.
Boxwood is modern and usually full of adults; here's their webpage.
There are a couple of loops from the clubhouse below, one that's 86km long, is on Strava here, and a shorter one of 67km here.