Place chocolate in a medium bowl.
Cook half-and-half and fat-free half-and-half in a small, heavy saucepan over medium heat until mixture steams and bubbles form around edges. Remove from heat. Pour hot half-and-half mixture over chocolate, stirring constantly until melted and smooth. Serve immediately with cake squares, strawberries, and banana slices, if desired.
Note: For testing purposes only, we used Ghirardelli Dark Chocolate.
Per 2-tablespoon serving of sauce with 1/12 of angel food cake, 4 strawberries, and 1/2 banana: Calories 307 (31% from fat); Fat 10.4g (sat 5.9g, mono 0.3g, poly 0.1g); Protein 4.3g; Carb 55g; Fiber 5.8g; Chol 7mg; Iron 1.9mg; Sodium 224mg; Calc 65mg.