Then add the butter and peanuts. Cook and stir until mixture reaches 310 degrees (hard crack stage). Remove from heat and add vanilla and baking soda. Stir quickly and vigorously until well-mixed.
Peanut brittle is a smooth, flat candy broken into shards with peanuts embedded inside. It is buttery, crunchy, nutty — and will add some West Virginia folklore flare to your platter.