Spread 1 1/2 teaspoons chocolate-hazelnut spread evenly over 2 very thin slices of bread. Top each with 2 slices of pear. Spread 1/2 teaspoon hazelnut spread over each of another 2 slices of bread; sandwich onto pear slices. Grill sandwiches in a panini press until golden on both sides (about 1–2 minutes per side). Halve sandwiches; serve.