This lowercase #DutchIJ is part of a wordmark, based on Museo by @exljbris, in which the outermost elements act as (symmetrical) brackets. That may be why there are no tittles or the like – which makes it more likely that the glyph is interpreted as a ‘y’ by non-native readers.
Interestingly enough, the shop maintains both URLs, kaasvanderley.nl (with y) and kaasvanderleij.nl (with ij).