Combine barbecue sauce, marmalade, garlic and mustard in a small bowl. Reserve ¼ cup.
Line a baking sheet with parchment paper and spread out the chicken legs. Brush the tops with half of the barbecue sauce.
Bake for 20 minutes.
Turn legs over and brush the other side with the rest of the sauce. If you have a convection oven, you can turn it on now.
Bake for 20 more minutes or until thermometer inserted in thickest part of the leg reads 165 degrees Fahrenheit.
Drizzle with the remaining sauce.
Video
Notes
Note - I gave a weight for the chicken legs, but really it depends on how many each person will eat. In this case I used 10 chicken legs. To brown the legs a bit more, I turned on my convection oven for the second half of the baking. If you don't have a convection oven and want to brown the legs more, you could place them under the broiler, but remove the parchment paper first!