  We present the first rest-frame UV population study of 17 heavily reddened,
high-luminosity (E(B-V)$_{\rm{QSO}}\gtrsim$ 0.5; L$_{\rm{bol}}>$
10$^{46}$ergs$^{-1}$) broad-line quasars at $1.5 < z < 2.7$. We combine the
first year of deep, optical, ground-based observations from the Dark Energy
Survey (DES) with the near infrared VISTA Hemisphere Survey (VHS) and UKIDSS
Large Area Survey (ULAS) data, from which the reddened quasars were initially
identified. We demonstrate that the significant dust reddening towards the
quasar in our sample allows host galaxy emission to be detected at the
rest-frame UV wavelengths probed by the DES photometry. By exploiting this
reddening effect, we disentangle the quasar emission from that of the host
galaxy via spectral energy distribution (SED) fitting. We find evidence for a
relatively unobscured, star-forming host galaxy in at least ten quasars, with a
further three quasars exhibiting emission consistent with either star formation
or scattered light. From the rest-frame UV emission, we derive instantaneous,
dust-corrected star formation rates (SFRs) in the range 25 < SFR$_{\rm{UV}}$ <
365 M$_{\odot}$yr$^{-1}$, with an average SFR$_{\rm{UV}}$ = 130 $\pm$ 95
M$_{\odot}$yr$^{-1}$. We find a broad correlation between SFR$_{\rm{UV}}$ and
the bolometric quasar luminosity. Overall, our results show evidence for coeval
star formation and black hole accretion occurring in luminous, reddened quasars
at the peak epoch of galaxy formation.
