Place the chiles in a saucepan and add 1 can chicken broth. Fill the can with water and add it to the pan. Make sure the chiles are submerged in the liquid.
Bring to a boil. Boil 5 minutes. Turn off the heat, cover, and allow to sit for 30 minutes.
Remove peppers from the liquid. Return liquid to a boil and reduce to half to about 1 cup.
Allow peppers and liquid to cool.
Meanwhile, heat 2 tablespoons of vegetable oil in a large skillet to medium temperature.
Add ancho chile powder, garlic powder, oregano, cumin, salt, and pepper. Bring to almost a boil.
Add vinegar and pineapple juice. Bring to a boil and immediately remove from heat.
Allow the liquid to cool completely.
To a blender add the guajillo chiles, the reduced guajillo liquid, and the vegetable oil-spice mixture. Pulse until pureed and smooth.
For the burgers
Add 2 tablespoon seasoning mixture to the ground pork and mix into the meat.
Pat meat into burgers. I made large 1/4 pound burgers. You can make any size then adjust your toppings accordingly.
Cover burgers in seasoning sauce, for 30 minutes to 1 hour turning occasionally.
Cook either on a stovetop or grill for 5 to 6 minutes per side on med-high heat. Turn just once and do not mash this will press the juices and flavor out.
Grill or cook on the stovetop the pineapple slices for 60-90 seconds per side until heated through
Build your burger
Place burger on the bottom bun, top with cheese, grilled pineapple slice, red onion, chopped cilantro, sauce and/or mayo, optional toppings.