1. Coat the lollipop molds with nonstick cooking spray. Place lollipop sticks in the molds.2. Combine the sugar, water, and corn syrup in a large, heavy saucepan. Bring to a boil over medium-high heat.3. Continue cooking until the mixture reaches 300°F/149°C (hard-crack stage). Immediately remove the saucepan from the heat.4. Add the citric acid, lemon oil, and food coloring and stir to combine. (Be careful to keep your face away from the pan, as the fumes can sting your eyes.)5. Pour the mixture into a heatproof measuring container with a spout. or a candy funnel. Divide the mixture among the prepared molds.6. Let the lollipops cool and harden, about 15 minutes, before removing them from the molds.7. For the Sour Powder: mix the confectioner's sugar and citric acid together in a bowl8. Dip the lollipops in the mixture to coat. Storage: wrap in cellophane bags, twist-tied shut in a cool, dry place for up to one month