Snap off and discard woody bases from asparagus. Arrange spears in a 9x9x2-inch baking pan. Brush with olive oil and sprinkle with half of the salt and pepper. Broil 3 to 4 inches from heat for 3 to 5 minutes or until crisp-tender, rearranging halfway through cooking time. Cool; bias-slice asparagus into 2-inch pieces.
In a medium bowl combine ricotta, lemon peel, garlic, rosemary, and remaining half of the salt and pepper. Spread ricotta mixture on toasted bread slices. Arrange cooked asparagus pieces on ricotta mixture.