I'm a huge writer of Spuffy baby fics here are a few
Buffy the vampire: Runner up in the COH Consorted World Award. A huge thanks to both my Beta's Burnkitty & Pixiecorn hugs. Set season 5, Very AU Spike is the slayer and Buffy is a vampire. When Dawn is taken by Glory, Buffy and Spike must band together to try and save her but will one off them end up trading their life for hers?http://spikeluver.com/SpuffyRealm/viewstory.php?sid=29810&warning=NC-17
Keeping secrets: Armed with fake I.D's 16 year old Elizabeth Buffy Summers and her best friend Cordeila Giles head out to L.A's hottest club intending on meeting up with Cordy's older, secret boyfriend Xander but when Cordy and Xander bail on Buffy she meets the man of her dreams Spike.
He is everything she has ever wanted in a guy fun, smart, sexy, and a wonderful lover only problem is he is 22 year old collage student and thinks she is the same not a 16 year old high school student.
How will Spike react when he discovers the truth? will he be able to forgive her? will he be able to put her age aside? and is her age the only secret she is keeping from him?http://spikeluver.com/SpuffyRealm/viewstory.php?sid=35414
Tricky Propositions: Set beginning of season 5 slightly AU, No Glory or Dawn.
Buffy and the gang come into contact with a prophecy that will change their lives forever. When Buffy finds herself faced with an impossible decision, she finds herself with the task of propositioning an unlikely alli.
Will Buffy be able to do what must be done to save the world? Will she be able to save her relationship with Riley? After everything is said and done, will she even want to? http://spikeluver.com/SpuffyRealm/viewstory.php?sid=33147
other ones i know of not written by me are:
Guilty pleasures By Ashlee: **COMPLETE** When William 'Spike' Bradley accepts a teaching position at Sunnydale High School, the last thing he expected was to meet the woman of his dreams. Especially considering the woman in question is his student. http://spikeluver.com/SpuffyRealm/viewstory.php?sid=6120
It matters to me By Ashlee: Buffy Summers has had a crush on Spike Giles since she moved to town. However, Spike never acknowledged Buffy while they were in school together. When Buffy starts working with Spike at the Magic Box, a tentative friendship is formed. The two grow closer until....http://spikeluver.com/SpuffyRealm/viewstory.php?sid=4658
Third times the charm By TammyAsh666: Spike never came back in "The Harsh Light of Day," instead returning a year later to find that things aren't exactly how he left them.http://spikeluver.com/SpuffyRealm/viewstory.php?sid=33755
That's all i can think of atm hope that helps.