Melt butter in a small saucepan over medium heat; add minced garlic, and sauté 1 minute or until tender. Remove from heat.
Place bread slices on a baking sheet; brush 1 side of each bread slice with butter mixture. Top evenly with Parmesan cheese and rosemary, if desired.
Bake at 375° for 10 to 12 minutes or until toasted.