Combine the basil, garlic, salt and pepper in a food processor. Reserve 2 tablespoons of the pine nuts and add the rest to the basil. Process until the pine nuts are ground. With the motor running, drizzle in the olive oil. Add the soft cheese and pulse until smooth and creamy.
Shortly before serving, make an X on the bottom side (opposite the stalk) of each cherry tomato with a serrated or sharp paring knife. Scoop out the seeds with a grapefruit spoon or your fingertips, taking care to keep the tomatoes intact. Scrape the pesto cheese filling into a piping bag fitted with a star nozzle, or small plastic food bag with a small hole snipped in one corner. Pipe a rosette of filling into each cherry tomato cavity. Garnish the cherry tomatoes with the remaining pine nuts.