MIX graham crumbs, butter and sugar until blended; press onto bottoms of 10 paper-lined muffin cups. Spoon 1/2 cup dulce de leche evenly over crusts; sprinkle with 1/3 cup nuts.
BEAT cream cheese and marshmallow creme in small bowl with mixer until blended. Add 2 Tbsp. of the remaining dulce de leche; mix well. Spoon into muffin cups; top with marshmallows.
DRIZZLE with chocolate syrup and remaining dulce de leche; sprinkle with remaining nuts. Refrigerate 3 hours.