Add the onion and garlic, and sauté until soft and translucent, about 10 minutes.
Add all the remaining ingredients, and stir until combined.
Let the sauce simmer for 20-30 minutes, or until the it begins to thicken.
Taste and adjust the seasonings with salt and pepper if desired.
Let the sauce cool until just warm.
Process sauce until smooth.
Let sauce cool until room temperature.
Cover, and store, refrigerated, for up to 2 weeks.
For the sliders
Preheat oven to 250 F.
Place brisket fat side down in pan.
Pour Dr Pepper over brisket.
Pour 3 tablespoons liquid smoke over brisket.
Sprinkle salt and pepper evenly over brisket.
Cover tightly with foil, and cook until brisket reaches 185 F, about 3-4 hours.
If you want a stronger smoke flavor, pour 3 additional tablespoons of liquid smoke over brisket during the last 1 hour of cooking. I like to pour some of the barbecue sauce over the top of the brisket at this point, too.
Once the brisket has reached temperature, remove it from the oven, and carefully remove the foil (there will be a big rush of steam).
Let the brisket sit for 15 minutes.
Thinly slice or chop the brisket and serve on slider buns.
Top with your favorite toppings, and enjoy!
Notes
Nutrition facts include slider bun but not toppings.