Spread a large piece of parchment paper onto a countertop or table. Lightly butter the parchment paper or spray it with non-stick baking spray.

In a heavy saucepan over medium heat, add the sugar, water and light and dark corn syrups and stir until the sugar is dissolved.

Increase the heat to medium-high, and boil the mixture, stirring occasionally, until a candy thermometer registers the “soft-crack” stage, 260º, about 30 minutes.

Add the peanuts and the butter and continue to cook the mixture until it reaches “hard-crack” stage at 290º, about 10 more minutes.

The mixture will reach 290º very quickly. Remove the pan from the heat promptly so that the mixture does not burn.

Immediately spread the hot sugar and peanut mixture onto the parchment paper using a metal spatula. The candy should be about 1/8” thick.

Let the peanut brittle cool on the parchment paper to room temperature before breaking it into pieces. Don’t refrigerate; instead, store it in an airtight container for up to three weeks.