Technically, it sounds more like "ciasta." A Russian Ч sounds more like Ć than "cz," not quite as palatalized but not retroflex either. It's pretty much the same as English "ch."
Ukrainian and Belarusian Ч are retroflex exactly like Polish "cz" when not palatalized by a soft vowel or ь. Probably because Ruthenians were under Poland for 400 years.