In a small saucepan, heat butter over medium heat until golden brown, about 7 minutes. Remove from the heat. Add chocolate; stir until smooth.
In a large bowl, combine the eggs, sugars and vanilla; whisk in chocolate mixture. Combine the flour, cocoa and salt; add to egg mixture and stir until smooth. Line a 15-in. x 10-in. x 1-in. baking pan with waxed paper and grease the paper; spread batter evenly into prepared pan.
In a small bowl, beat the cream cheese, sugar and cornstarch until smooth; beat in egg and vanilla. Gently spread over chocolate layer. Drizzle caramel topping over cream cheese layer in vertical lines about 1 in. apart. Use a toothpick to draw right angles across the drizzled lines, about 1/2 in. apart.
Bake at 325° for 15-18 minutes or until a toothpick inserted near the center comes out clean (do not overbake). Cool on a wire rack for 1 hour. Refrigerate for 1 hour before removing from pan. Discard waxed paper. Cut with a 3-in. x 1-in. crescent-shaped cookie cutter. Store in an airtight container in the refrigerator. Yield: 20 bars.
