It is a cylinder like sponge cake, or I should say “a roll cake”, with white cream inside. This is a famous sweets in Niigata of northern part of JAPAN. Bandaitaiko by Osakaya is a very good choice for souvenir when you visit Niigata.
“Bandai Taiko” is Strongly Recommended for Souvenir of Niigata
Agony or Fun?! Second Language Learning 