How to Make It
Stir together first 5 ingredients (through rosemary) in a medium saucepan. Bring to a boil over medium, mashing berries to break them down. Reduce heat to medium-low; cook, stirring often, until thickened, about 6 minutes. Remove from heat; cool slightly, about 10 minutes. Discard rosemary sprigs.
Preheat oven to 350°F. Coat an 11- x 7-inch glass baking dish with cooking spray. Stir together oats, flour, brown sugar, and salt in a medium bowl. Add butter and vanilla, and stir until all flour is moistened. Reserve 2/3 cup oat mixture.
Pat remaining oat mixture in an even layer in prepared dish. Top with raspberry mixture, spreading to edges. Sprinkle reserved oat mixture over raspberry mixture. Bake at 350°F until lightly browned, about 35 minutes. Cool completely on a wire rack. Cut into 16 (3 1/2- x 1 1/3-inch) bars. Store in an airtight container up to 2 days.