Begin by softening 8 ounces of cream cheese at room temperature for about 30 minutes until it's pliable. In a medium mixing bowl, combine the softened cream cheese with 1/4 cup of blackberry jam. Blend until smooth and creamy.

Gently fold in 1 cup of fresh blackberries, finely chopped jalapeño, 2 tablespoons of sliced green onions, and 1 tablespoon of chopped cilantro if desired. Ensure everything is evenly mixed without overworking the cheese.

Lay out a long piece of plastic wrap and scoop the cheese mixture onto the center, shaping it into a log, roughly 1.5 to 2 inches in diameter. Use the plastic wrap to help form and tighten the log.

Wrap the formed log tightly with plastic wrap, then place it in the refrigerator for at least 1 hour to firm up and allow flavors to meld.

After chilling, unroll the plastic wrap from the log. If desired, roll the log in a mix of chopped nuts. Slice the log into rounds about half an inch thick for serving.