This is the 12850th most frequent Russian word.
кусочков
"Кусочков" means "pieces" (genitive plural form in Russian).
In this sentence, 'кусочков' means 'pieces' and is used in the genitive plural form to denote that there are many small parts of the cake prepared for a purpose.
Я приготовил множество маленьких кусочков торта для наших гостей.
I prepared many small pieces of cake for our guests.
Here, 'кусочков' is in the plural genitive form and is used to describe a partitive quantity of cheese left on the table.
На столе осталось несколько кусочков сыра.
There are a few pieces of cheese left on the table.
While not using 'кусочков' directly, 'кусочки' is the nominative plural form, highlighting how pieces refer to parts of a puzzle that are being connected.