Cut chicken into 1-inch strips. Add to a glass container with a lid or to a large freezer bag.
In a medium bowl, add buttermilk and sugar. Add half of each of the garam masala, salt, coriander, turmeric, garlic powder, pepper, and ginger. Add all of the Armenian pepper. Whisk everything together.
Pour marinade over chicken pieces. Cover and refrigerate for at least 6 hours or overnight. Remove chicken from refrigerator 1 hour before cooking.
Preheat oven to 400F. Line a rimmed baking sheet with parchment paper.
Mix together flour, panko, cornmeal and remaining spices in a large bowl.
Remove chicken from marinade and dab lightly with paper towels to absorb excess marinade. I recommend wearing latex food prep gloves for the rest of this step. Place each piece of chicken in the breading mix, pressing coating into the chicken to ensure it is well coated. Put breaded chicken on a plate until the baking pan is ready.
Cube butter and put it on the baking tray. Put the tray in the oven, just until the butter melts. Remove pan from oven and place breaded chicken pieces on the tray. Return the tray to the oven.
Bake chicken for about 10 minutes. Carefully flip, and continue baking until done, approximately5-7 minutes, depending on the size of the chicken pieces. To make the chicken crispy, turn on the broiler for the last few minutes of cooking time. Serve with mango chutney or raita.