Remove the pan of cauliflower from the oven and turn the broiler on.
Using a wooden spoon, push the cauliflower to one side of the sheet pan.
Pat the shrimp dry and season all over with salt, pepper, cayenne powder, and adobo seasoning. I used few generous shakes each of the cayenne powder and adobo seasoning, but use as much of the spices as you like to your preference.
Carefully transfer the shrimp, in an even layer, to the empty side of the sheet pan. Flip them so both sides pick up a bit of the spiced oil from the cauliflower.
Transfer the sheet pan to the broiler for 3-4 minutes or until the shrimp are opaque and the cauliflower has charred a bit on the top. Remove from the broiler and set aside.