Separate egg whites and yolks; set aside. With vegetable peeler, remove peel from lemon in long strips and place in medium saucepan. Juice lemon into a separate small saucepan and set aside.
Combine half-and-half and sugar with lemon peel. Cook over medium-low heat just until mixture comes to simmer. Whisk egg yolks in large bowl; slowly whisk in half-and-half mixture. Pour mixture through fine mesh sieve back into pan to remove peel. Cook and stir gently over medium-low heat for about 15 minutes or until mixture just begins to thicken and bubble. Remove from heat; stir in vanilla. Quickly cool custard by placing the saucepan in a large bowl of ice water for 1 minute, stirring constantly. Transfer to a bowl. Cover; set aside.
In shallow dish whisk together egg whites, cinnamon, and salt. In 12-inch nonstick skillet heat butter over medium heat. Dip cut sides of cake into egg mixture; add to skillet in 2 batches. Brown about 2 to 3 minutes per side; set aside.
Add apricot preserves to lemon juice in small saucepan. Heat over medium-high heat until preserves are melted.
To serve, pour some of the vanilla custard onto a plate or in a shallow bowl. Top with cake, preserves, lemon peel, and mint. Makes 10 servings.