On baking sheet, spread out bread slices. Lightly drizzle both sides with olive oil, then broil in oven for 2-3 minutes on each side—until the bread is lightly golden and crunchy.
In small bowl, cream together goat cheese, pepper, a pinch of salt, and thyme. Set aside.
In medium bowl, pour lemon juice over apple slices to prevent apples from browning. Drain any remaining lemon juice and set aside.
Smudge a dollop of goat cheese on each crostini, and then top with an apple slice, lemon zest, and thyme.