Medovnik
Medovnik is a multi layer cake that translates to "honey cake" for good reason as honey is its main ingredient. Made from sponge cake, layered with a cream filling, and often covered in nuts, Medovnik is known for its lengthy preparation time.
Generally the condensed milk is made the day before the cake. The cake itself takes about 3 hours to make and then after it's all put together, it's left to rest refrigerated until the next day so that all the flavors blend in nicely.
Of course, Medovnik is one of those desserts that is truly worth the wait.