Put the 8 ounces softened goat cheese and 8 ounces softened cream cheese into a medium bowl.
Add 1/2 teaspoon garlic powder and 1/4 teaspoon fresh cracked black pepper. Mix until the cheeses are fully combined and smooth (use a hand mixer, wooden spoon, or sturdy fork).
Transfer the cheese mixture to an airtight container and refrigerate for at least 1 hour to let the flavors meld and to firm the mixture slightly.
When ready to assemble, stir the chilled cheese mixture briefly to make it spreadable if it has become very firm. Place the 24 crostini or toasted baguette slices on a serving platter.
Spread about 1/2 tablespoon of the cheese mixture onto each crostini.
Spoon pesto on top of each crostini, dividing the 1/2 cup of pesto among the 24 crostini.
Garnish each canapé with chopped fresh basil or parsley if desired, and serve immediately.