In medium microwavable bowl, microwave white chocolate and cajeta uncovered on High 1 minute, stir. Microwave 45 seconds longer; stir until smooth. Spread evenly over fudge layer. Sprinkle with 1 cup cashews; press gently into caramel layer. Sprinkle with salt. Refrigerate about 3 hours or until firm. Cut into 6 rows by 6 rows. Store covered at room temperature.