In a medium bowl, whisk together the BBQ sauce, grape jelly, brown sugar, ketchup, Worcestershire sauce, mustard, garlic powder, onion powder, smoked paprika, black pepper, and red pepper flakes (if using) until mostly smooth. The jelly may look a bit lumpy but will melt as it cooks.
1 1/2 cups BBQ sauce, 3/4 cup grape jelly, 1/4 cup brown sugar, 2 tablespoons ketchup, 1 tablespoon Worcestershire sauce, 1 tablespoon yellow mustard, 1/2 teaspoon garlic powder, 1/2 teaspoon onion powder, 1/4 teaspoon smoked paprika, 1/4 teaspoon black pepper, red pepper flakes
Place the little smokies sausages in a 3- to 4-quart slow cooker (use a larger crock if doubling the recipe).
2 14-ounce packages little smokies sausages
Pour the prepared BBQ sauce mixture evenly over the sausages. Gently stir to coat the sausages in the sauce.
2 14-ounce packages little smokies sausages, 1 1/2 cups BBQ sauce, 3/4 cup grape jelly, 1/4 cup brown sugar, 2 tablespoons ketchup, 1 tablespoon Worcestershire sauce, 1 tablespoon yellow mustard, 1/2 teaspoon garlic powder, 1/2 teaspoon onion powder, 1/4 teaspoon smoked paprika, 1/4 teaspoon black pepper, red pepper flakes
Cover and cook on LOW for 3–4 hours or on HIGH for 1 1/2–2 hours, stirring once or twice, until the sausages are heated through and the sauce is glossy and slightly thickened.
Switch the slow cooker to WARM for serving. Set out toothpicks or small forks and let guests serve themselves directly from the slow cooker.
For a stovetop version, add the BBQ sauce, grape jelly, brown sugar, ketchup, Worcestershire sauce, mustard, garlic powder, onion powder, smoked paprika, black pepper, and red pepper flakes to a medium saucepan or Dutch oven. Stir over medium heat until the jelly melts and the sauce is smooth.
1 1/2 cups BBQ sauce, 3/4 cup grape jelly, 1/4 cup brown sugar, 2 tablespoons ketchup, 1 tablespoon Worcestershire sauce, 1 tablespoon yellow mustard, 1/2 teaspoon garlic powder, 1/2 teaspoon onion powder, 1/4 teaspoon smoked paprika, 1/4 teaspoon black pepper, red pepper flakes
Stir in the little smokies sausages, coating them well in the sauce. Bring to a gentle simmer, then reduce heat to low and cook for 15–20 minutes, stirring every few minutes, until the sausages are heated through and the sauce has thickened slightly.
2 14-ounce packages little smokies sausages
Serve the sausages warm in a serving bowl, small warming dish, or directly from the pot. Keep covered when not serving so they stay hot and saucy.