It looks like a Banded Uromastyx. I don't believe adult Mali Uromastyx ever show any white coloration on their backs. In male Malis It's usually some shade of yellow. Also, unless they're melanistic and show no pattern at all, Mali Uromastyx should have some ocelli or spotting on their backs. At any rate it's a beautiful and healthy looking Uromastyx you've got there.

Here's a picture of my adult male Banded, who along with his mate, produced 13 young for me this year.