Scoop a tub of the flavored cream cheese into a piping bag with round tip (small or medium). Tie off end.
If using a small tip scoop a little of the cream cheese into center of cracker or cookie to pipe over. This is not necessary with a medium tip hole.
Pipe a line down center of cracker/cookie leaving space on each end. Then pipe a swirling snake like shape on each side of it to create each "brain".
Finally, simply squirt a little gel icing or hot sauce in a few spots around edge of the cream cheese brains and a little in center if you like.
Notes
I used a little different technique on the sweet vs the savory versions of these Halloween brain snacks. The effect of the ones piped with the smaller holed tip (OREO) look a little better to me, but the larger tip (used on RITZ) is faster, easier, and still creates a brain-like effect.