Paskha (also spelled pascha, or pasha; Russian: па́сха; [ˈpasxə]; “Easter”) is a festive dish made in Eastern Orthodox countries.
Estonian religious population is predominantly Christian. In 1845–1848, the movement from the Lutheran Church to the Russian Orthodox Church took place in all the southern Estonian counties and about 17% of the peasants in southern Estonia converted to Orthodoxy. Until then, Orthodoxy was mainly the religion of the local Russians and Seto (Setu) people.
Reason to change religion was hope to get land and better conditions.
So, lot of Russian Orthodox Church rituals and dish are still popular. I am personally do not like pasha. But pasha- inspired cake is very delicious.