Thanks for getting back to me, Rick. Here are the screenshots from the scope:
^^SPI Write: Yellow=CS, Orange=Clk, Green=MOSI, Purple=MISO
^^SPI Read, same signals
The key difference between my post and the two links you posted is that I am getting no response whatsoever from the MISO line. I suspect that the pin is faulty on the chip, but I am having the same issue on two different boosterpacks. What debugging steps do you suggest I take? The settings for non-SPI pins are in my code, attached to the original post.