  We report observations of the optical counterpart of the long gamma-ray burst
(LGRB) GRB 221009A. Due to the extreme rarity of being both nearby ($z =
0.151$) and highly energetic ($E_{\gamma,\mathrm{iso}} \geq 10^{54}$ erg), GRB
221009A offers a unique opportunity to probe the connection between massive
star core collapse and relativistic jet formation across a very broad range of
$\gamma$-ray properties. Adopting a phenomenological power-law model for the
afterglow and host galaxy estimates from high-resolution Hubble Space Telescope
imaging, we use Bayesian model comparison techniques to determine the
likelihood of an associated SN contributing excess flux to the optical light
curve. Though not conclusive, we find moderate evidence
($K_{\rm{Bayes}}=10^{1.2}$) for the presence of an additional component arising
from an associated supernova, SN 2022xiw, and find that it must be
substantially fainter ($<$ 67% as bright at the 99% confidence interval) than
SN 1998bw. Given the large and uncertain line-of-sight extinction, we attempt
to constrain the supernova parameters ($M_{\mathrm{Ni}}$, $M_{\mathrm{ej}}$,
and $E_{\mathrm{KE}}$) under several different assumptions with respect to the
host galaxy's extinction. We find properties that are broadly consistent with
previous GRB-associated SNe: $M_{\rm{Ni}}=0.05$ - $0.25 \, \rm{M_\odot}$,
$M_{\rm{ej}}=3.5$ - $11.1 \, \rm{M_\odot}$, and $E_{\rm{KE}} = (1.6$ - $5.2)
\times 10^{52} \, \rm{erg}$. We note that these properties are weakly
constrained due to the faintness of the supernova with respect to the afterglow
and host emission, but we do find a robust upper limit on the $M_{\rm{Ni}}$ of
$M_{\rm{Ni}}<0.36\, \rm{M_\odot}$. Given the tremendous range in isotropic
gamma-ray energy release exhibited by GRBs (7 orders of magnitude), the SN
emission appears to be decoupled from the central engine in these systems.
