Preheat the oven to 375°F (190°C).
Mix brown sugar, black pepper, and cayenne pepper in a bowl until combined.
Lay bacon strips on a parchment-lined baking sheet and sprinkle the seasoning mixture evenly over the bacon.
Bake for 20-25 minutes until bacon is crispy and caramelized, then transfer to a wire rack to cool.
Slice the baguette into 1/2-inch rounds and lightly brush both sides with olive oil.
Toast the baguette slices in the oven for 5-7 minutes until golden and crispy.
Combine softened cream cheese with maple syrup in a bowl, stirring until smooth.
Chop cooled bacon into small pieces.
Spread cream cheese mixture evenly over toasted baguette slices.
Top each crostini with chopped bacon, chopped chives, and diced jalapeño if using.
Garnish with fresh parsley and serve.