HEAT oven to 400°F.
PLACE baguette slices on foil-lined or parchment paper-lined baking sheet
.In a medium microwave-safe bowl, COMBINE cranberry sauce and orange zest, if using. Set aside.
In a small bowl, COMBINE melted butter and olive oil
BRUSH the tops of baguette slices with butter/olive oil mixture.
TOAST baguette slices for 7-8 minutes, until golden and crispy. REMOVE from oven
SLICE brie into thin pieces (about ¼ inch pieces).
PLACE 1 piece of brie onto each toasted baguette slice.
RETURN to the oven for about 3-5 minutes until brie begins to melt. REMOVE from oven.
HEAT cranberry sauce in the microwave until warm.
TOP each crostini with 1 teaspoon cranberry sauce. SERVE immediately.