Step 1: Prepare the Marinade

1. In a mixing bowl, combine Dr. Pepper, Worcestershire sauce, soy sauce, brown sugar, honey, garlic powder, onion powder, black pepper, smoked paprika, red pepper flakes, jalapeños, salt, and cayenne pepper (if using).
2. Stir well to ensure all ingredients are fully combined.

Step 2: Marinate the Beef

1. Place the thinly sliced beef in a large zip-top bag or shallow dish.
2. Pour the marinade over the beef, ensuring all pieces are coated.
3. Seal the bag or cover the dish and refrigerate for at least 6 hours (preferably overnight for maximum flavor).

Step 3: Prepare for Drying

1. Remove the beef from the marinade and pat dry with paper towels to remove excess moisture.
2. Arrange the slices in a single layer on a wire rack or directly on your dehydrator trays.

Step 4: Dry the Beef

Oven Method:

1. Preheat oven to 170°F (or the lowest setting).
2. Place a wire rack over a baking sheet and lay the beef slices on top.
3. Dry for 4-6 hours, flipping halfway through, until the jerky is firm but still pliable.

Dehydrator Method:

1. Arrange beef slices in a single layer on dehydrator trays.
2. Set to 160°F and dry for 4-6 hours, checking occasionally.

Step 5: Cool & Store

1. Allow the jerky to cool to room temperature before storing.
2. Store in an airtight container or vacuum-sealed bag at room temperature for up to 2 weeks (or refrigerate for longer storage).