I think that if you try this, you will be denied boarding at check-in.
There are two reasons for this:
First, airside transit without visa is intended for traveling from one country through the international transit area of a second country en route to a third country. Returning to the country of origin is not intended. Timatic, the system which airlines use to verify passenger documents, notes this.
Transit Without Visa (TWOV): Passing through an international transit area of the airport in order to board a connecting (or
to proceed by the same) flight, without entering the country (i.e. clearing immigration).
Unless stated otherwise, passengers wishing to TWOV must:
- be en-route to a third country (e.g. itinerary TYO-LON-TYO is not considered TWOV);
(In this case, it is not "stated otherwise" anywhere.)
Second, passengers flying on low cost carriers such as Air Asia cannot transit airside in Singapore. You would be required to clear immigration and check in lansdide for your return flight. Timatic also notes this.
TWOV (Transit Without Visa):
- Transit passengers holding 2 separate tickets can check in for the connecting flight in the international transit area, except when arriving/departing on a budget carrier. Budget carriers are: Air Asia (AK), Indonesia AirAsia (QZ), Thai AirAsia (FD), Air India Express (IX), Cebu Pacific Air (5J), Firefly (FY), Jetstar (JQ), Jetstar Asia (3K), Jetstar Pacific (BL), Lion Air (JT), Scoot (TZ), Spring Airlines (9C), Tigerair (TR) and VietJet Air (VJ).
Timatic output for your proposed itinerary
You will need a visa to visit Singapore, which as a resident of Malaysia ought not be too difficult to get on your own. If you have friends who are Singapore citizens or permanent residents, they can also apply for the visa on your behalf.
For returning to Malaysia, you need to ensure that your student pass/visa are still valid, or that you've obtained a re-entry permit.