Prepare the filling by mixing the chicken, refried beans, cheddar cheese, cumin, and chili powder in a large bowl.
Lay out flour tortillas on a clean surface and spoon a generous amount of the filling into the center of each tortilla.
Fold in the sides of the tortilla and then roll it up tightly to form the chimichanga.
Heat vegetable oil in a large skillet over medium heat until hot but not smoking.
Carefully place the chimichangas seam-side down in the hot oil and fry until golden brown on all sides, about 2-3 minutes per side.
Remove the chimichangas with a slotted spoon and drain on paper towels to remove excess oil.
Serve the chimichangas hot with sour cream and fresh cilantro on top.