In a small bowl, combine the chili powder, salt, garlic powder, and ground cumin. Divide this spice mixture roughly in half—you'll use one portion for the chicken and the other for the vegetables. Place the cooked chicken in a separate bowl and sprinkle half of the spice mix over it, stirring well to coat evenly. Set the chicken aside while you prepare the vegetables.

Heat 1 tablespoon of olive oil in a large skillet over medium heat. Once hot, add the diced onion and both bell peppers, then sprinkle the remaining half of the spice mixture over them and stir to coat. Cook for 6 to 8 minutes, stirring occasionally, until the vegetables are tender and slightly softened. Add hot sauce to taste if desired, then stir in the fresh cilantro. Transfer the cooked vegetables to the bowl with the seasoned chicken and stir together until well combined. I like to let this filling cool for a minute or two before assembling—it makes the cheese less likely to melt prematurely and gives you more control over the quesadilla assembly.

Lay out one tortilla on a clean work surface. Sprinkle about 1/4 of the pepper jack cheese over one half of the tortilla, then top with about 1/4 of the chicken and vegetable filling from Step 2. Sprinkle additional pepper jack and cheddar cheese over the filling. Fold the empty half of the tortilla over the filling and press gently to seal. Repeat this process with the remaining tortillas and filling to create four assembled quesadillas. Arrange them on a plate or cutting board so they're ready to cook.

Wipe out the skillet from Step 2 and heat it over medium to medium-low heat with a light coating of canola or vegetable oil. Working in batches, place 1 to 2 quesadillas in the pan and press down gently with a spatula to help the cheese melt and create contact between the tortilla and the heat. Cook for about 4 minutes until the bottom is golden brown and crispy, then carefully flip and cook the other side for 2 more minutes until it's equally golden. I find that keeping the heat at medium or just below prevents the tortilla from burning before the cheese fully melts—patience here makes all the difference. Transfer the cooked quesadillas to a cutting board and let them cool for a minute or two.

Using a sharp knife or pizza cutter, slice each quesadilla into triangular wedges—cutting from corner to corner or into thirds works well. Arrange the wedges on a serving platter and serve hot alongside salsa, guacamole, and sour cream for dipping and topping.