Preheat oven to 325 degrees. Zest one half of a lemon and set aside for juicing later. Take the other 1 1/2 lemons and slice thinly into rings. Remove any seeds. Line a baking sheet with non stick tin foil and spray with the cooking spray. Place the lemon slices on sheet. Spray the lemons with the cooking spray. Bake for 20-25 minutes until lightly brown. Remove from oven and set aside.
Adapted from For a Love of Cooking