1. Preheat oven to 375 degrees. Combine ketchup, mustard, and garlic powder in a mixing bowl. Add chicken and mix to coat. Allow to marinate 20–30 minutes.
2. Working with one chicken breast at a time, wrap hot dog with chicken and place seam-side down in a baking pan. Place chicken dogs side by side, leaving a bit of space between portions. Spoon remaining marinade over chicken and cover with foil.
3. Bake for 35 minutes, or until chicken is cooked through. (You can tell if it’s done by piercing the chicken with a fork; if clear juices run out, it’s ready.)
4. Cut a slit into each bun from the top down, three-quarters of the way through. Remove chicken dogs from oven and insert each one into a bun. Top with additional ketchup, sauerkraut, and/or thinly sliced sour pickles if desired.