There is a new CAN version which allows longer data packets, but it is not supported by most CAN controllers.
What CAN controller do you use and why can't you split the data into 8-byte packets?
CAN frame format is defined in the specification. It says the DATA field can be 0 to 8 bytes long.
In so far the literal answer is: "You can't do that".
To send larger data entities, you have to define an application layer on top of the basic CAN data transmission that combines multiple frames in a meaningful way to represent larger data entities. You can either refer to existing protocol stacks like CANopen or define your own.