Deliberately breaking a fast observed during the month of Ramaḍān without a valid excuse entails not only making up (qaḍāʾ) that fast, but also an additional penal obligation known as kaffārah (expiation).
The kaffārah for breaking a Ramaḍān fast consists, in order, of emancipating a slave; if one is unable to do so, fasting consecutively for sixty days; and if one is unable to do that, feeding sixty poor persons for one day each. Since slavery no longer exists in the present day, the primary obligation for those who are able is to fast for sixty consecutive days.
It must be borne in mind that breaking the fast without a legitimate excuse is not merely a juridical violation that entails qaḍāʾ or kaffārah; it is also a serious sin and an act fundamentally incompatible with conscious servitude to Allah. Such behavior amounts to knowingly treating a clear divine command lightly and undermines the very spirit of worship. Whether or not qaḍāʾ or kaffārah is required, deliberately invalidating an act of worship without excuse is sinful, entails accountability in the Hereafter, and is wholly inconsistent with the awareness of servitude owed to Allah.