Halve the lemons and remove the seeds. Make 2 slits along the membranes of each half and stuff a dried bay leaf into each slit. Set the lemons cut side up on a baking sheet and bake in a 250° oven for 2 hours. Transfer the roasted lemons to a glass measuring cup and add the Simple Syrup. Cover and refrigerate overnight. Strain the syrup into an airtight container, squeezing the juice from each lemon, and refrigerate for up to 1 week.