Is there a way for a gnome to grab the Favored Class Options from an aasimar instead of itself?

Question

I am looking into building a Gnome bard. I prefer the alternate favored bonus from the Aasimar race. Is there a way for a gnome to grab the Favored Class Options from an aasimar instead of itself?

Aasimar

Choose one bardic performance; treat the bard as +1/6 level higher when determining the effects of that performance.

Gnome

Add +1 to the bard’s total number of bardic performance rounds per day.

I want to be physically and culturally a gnome. I imagine myself traveling in the wild looking for inspiration, friends and knowledge. I want to ride a medium sized goat. My size should be small. If the flavor stays, I am fine to be an aasimar on the sheet.

I won’t pick the Prankster template or anything like that so far. I plan to build a vanilla bard.

If possible I am looking for a raw solution, but I am fine with third-party.

Answer 1

Inspired by @KRyan comment, I digged a bit the non-human aasimar part:

Non-human aasimars have the same statistics as human aasimars with the exception of size. Thus a halfling aasimar is Small but otherwise possesses the same statistics and abilities as a human aasimar—the difference is purely cosmetic. Non-human aasimars do not possess any of the racial abilities of their base race. However, they are usually raised in the same cultural context as other members of their base race, and thus generally adopt the same fighting style as their peers, use the same types of weapons and armor, and study the same skills.

(emphasis mine)

It fits a lot with what OP is looking for. Is there a way for a gnome to grab the Favored Class Options from an aasimar instead of itself? A way to achieve this is to be mechanically an aasimar and flavorfully a gnome.

In bonus, you should be able to use, with your base race, the altered race feature:

Scion of Humanity Some aasimars’ heavenly ancestry is extremely distant. An aasimar with this racial trait counts as an outsider (native) and a humanoid (human) for any effect related to race, including feat prerequisites and spells that affect humanoids. She can pass for human without using the Disguise skill. This racial trait replaces the Celestial language and alters the native subtype.

Answer 2

You can be a gnome aasimar, so you don't count as a gnome. Take scion of humanity, making you count as human and an outsider. Then you can take the human feat racial heritage and choose gnome. You would then count as and have your choice of favored class options from aasimar, human, or gnome. As well as feat choices, etc., and you would have a small size.

I'm hoping that helped. I also hope it isn't used to upset your GM with shenanigans.