Line a baking sheet with parchment paper or a silicone baking mat and set it within arm's reach of your stove.

Pour 3/4 cup water, 3/4 cup light corn syrup, and 2 cups granulated sugar into a heavy-bottomed saucepan without stirring.

Sprinkle 1/4 teaspoon cream of tartar over the mixture and place the pan over medium heat.

Clip a candy thermometer to the side of the pan and heat the mixture without stirring until it boils and turns clear, about 5 to 7 minutes.

Continue cooking without stirring until the thermometer reads 300 to 310°F (hard crack stage), about 8 to 12 minutes more.

Remove the pan from heat and let bubbling subside for 10 seconds, then quickly stir in 1/2 teaspoon flavoring oil and 1/4 teaspoon food coloring.

If using, add 1/8 teaspoon baking soda and stir gently for 1 to 2 seconds until the mixture puffs slightly.

Pour the hot syrup onto the prepared baking sheet in a thin layer and let it cool and harden at room temperature for 30 to 45 minutes.

Once cooled, break the candy sheet into pieces by hand or cut with oiled scissors and dust with powdered sugar if desired.