STM32L471RGT6 32 bit SPI

As a pair of 16-bit words, or as 4-bytes, in a consecutive fashion, and arranged to suit whatever MSB-LSB and endian form you need.

Of course. Send 16-bits, twice. Newer STM32s can send 32 bits in one write to the SPI data register, but L4 is limited to 16 bits at once.

Thank you Pavel, I was going to use NSS but I was thinking that that won't work as comms will shutdown after the first 16 bytes. I guess I will just have to manually control NSS. 
Cheers

Richard