Preheat oven to 450 degrees F. Line a large baking pan with aluminum foil (for easy clean up).
Mix all sauce ingredients in a small bowl.
Cut ribs into serving portions, single ribs for regular spare ribs and 2 ribs for baby backs. Lay ribs in a single layer in prepared baking pan. Sprinkle with salt and pepper.
Bake at 450 degrees F for 15 minutes. Remove from oven, drain all liquid from the pan and reduce oven temp to 350 degrees F.
Pour sauce over ribs and cover pan with foil. Place in 350 degree oven and bake for 1 1/2 hours, basting with sauce every 30 minutes. Remove foil cover during last 30 minutes of baking time.
Coat ribs with thickened sauce in the bottom of the pan and serve immediately.
SLOW COOKER
Place all ingredients in slow cooker and cook for 6-8 hours on low. Sauce may be reduced in a saucepan on the stovetop if desired
Notes
*Strained baby food peaches are fine, but you can also puree drained, canned peaches in a blender, strainer attachment or Ninja