Every Texan loves their Dr. Pepper, and that soft-drink takes this is basic sweet BBQ sauce and gives it a Texas edge. You might want to make a double recipe, because you'll find yourself putting this on EVERYTHING!!!!
In a heavy saucepan, melt the butter. Sauté the onion and garlic in the butter until translucent, about 10 minutes.
Add all the remaining ingredients and simmer for about 15 minutes, until the flavors have blended. Taste and adjust the seasonings with salt and pepper, if needed. Don't overseason, because the meat should already have a rub on it.
Continue cooking until the sauce begins to thicken, 20 to 30 minutes.
Let the sauce cool for about 10 minutes or until it is warm but no longer "boiling" hot. Puree with an immersion or traditional blender-this will make the sauce thicker. Let cool.
The sauce will keep, tightly covered, in the refrigerator for up to 2 weeks.
To use: Brush it on well-seasoned meat 5 to 15 minutes before the cooking time is finished. If desired, serve extra on the side.