(From my mom-and-pop archives; this little shop closed, after 30 years, in 2014.) In summer, when blueberries are in season, these nubbly half-moons are wonderful with a little butter and sugar. To my taste, however, plum pierogi — like the one shown below in cutaway view, from an autumn visit — are better with sour cream.
Sweet or sour? In truth, it's hard to go wrong either way.
First Avenue Pierogi & Deli
130 First Ave. (7th-8th Sts.), Manhattan