Yes, cracker is a Scrabble word!

Noun

1. A thin crisp wafer made of flour and water with or without leavening and shortening; unsweetened or semisweet

2. A poor White person in the southern United States

3. A programmer who cracks (gains unauthorized access to) computers, typically to do malicious things

4. Firework consisting of a small explosive charge and fuse in a heavy paper casing

5. A party favor consisting of a paper roll (usually containing candy or a small favor) that pops when pulled at both ends