Yes, you can do this on your macbook.
All you have to do is go into utilities (shift-apple-U in finder), Audio/Midi setup.
Create a new device by clicking the little plus sign. It'll be called aggregate device.
Now click on it, and select your two interfaces with the check boxes.
The aggregate is a virtual interface that encapsulates your two real interfaces.
Finally, in your audio recording software, select aggregate device as your hardware.
You might have to setup your default outputs again, but see how you go.