  We present ultraviolet (UV) and optical photometry and spectra of the
1999aa-like supernova (SN) iPTF14bdn. The UV data were observed using the Swift
Ultraviolet/Optical Telescope (UVOT) and constitute the first UV spectral
series of a 1999aa-like SN. From the photometry we measure $\Delta m_{15}({\it
B})\,=\,0.84 \pm0.05$ mag and blue UV colors at epochs earlier than $-5$ days.
The spectra show that the early-time blue colors are the result of less
absorption between $2800 - 3200 \,\AA~$ than is present in normal SNe Ia. Using
model spectra fits of the data at $-10 $ and $+10 $ days, we identify the
origin of this spectral feature to be a temperature effect in which doubly
ionized iron group elements create an opacity 'window'. We determine that the
detection of high temperatures and large quantities of iron group elements at
early epochs imply the mixing of a high Ni mass into the outer layers of the SN
ejecta. We also identify the source of the I-band secondary maximum in
iPTF14bdn to be the decay of Fe III to Fe II, as is seen in normal SNe Ia.
