Toasting the chiles and garlic. Roast the garlic cloves on a griddle or heavy skillet over medium heat, turning frequently, until blackened in spots and Very soft, about 15 minutes. Remove, cool, skin and roughly chop. While the garlic is roasting, tear the chiles into flat pieces and toast them a few at a time: Use a metal spatula to press them firmly against the hot surface for a few seconds, until they blister, crackle and change color, then flip them over and press them flat to toast the other side. Soaking the dried chiles. Break the chiles into a small bowl, cover with boiling water, weight with a plate to keep submerged and soak 30 minutes. Drain, tear into smaller pieces, place in a blender jar and add the garlic. Finishing the Adobo. In a mortar or spice grinder, pulverize the cinnamon, cloves, peppercorns, bay leaves and cumin. Add the chiles along with the oregano, thyme, salt, vinegar and 3 Tb water. With a long series of blender pulses, reduce the mixture to a paste. Run the blender for a few seconds until the mixture clogs, then scrape down the sides with a spatula and stir; repeat a dozen times or more until the mixture is smooth. Don't add water unless absolutely necessary or this marinating paste won't do its job well. Strain the paste through a medium-mesh sieve into a noncorrosive container with a tight-fitting lid. Cover and refrigerate.
Considerations: After soaking the chiles, they can be put through a foley food mill to remove the skins and the seeds. Add this puree along with the garlic to the small blender jar and proceed. If this is done, and the mixture is put together in a small blender jar, and pulsed, scraped down, and mixed very well the final sieving can be eliminated.
All of the chiles can be Ancho or Guajillo. You can substitute 3 1/2 ounces of California or New Mexican chiles for the above chiles but the flavor will be light.
Adobo with powdered chiles: For a darker, stronger tasting adobo made without the tedious series of blender runs, roast the chiles and garlic as directed above, then pulverize the chiles with the cinnamon, cloves, pepper, bay leaves and cumin in several batches in a spice grinder; sift through a medium-mesh sieve. Skin the garlic and mash it to a smooth paste. Mix with the powdered chile mixture, oregano, thyme, salt, vinegar and 6 Tb water. Store as directed above.