This easy keto sugar-free peanut brittle is a classic, sweet hard candy that is made on the stovetop with only 6 basic low-carb ingredients. It's so close to the original sweet, salty, and crunchy old-fashioned candy that it will knock your socks off, but there's no need to feel guilty because it only has 2 net carbs per serving!
Line a large baking sheet with parchment paper. Set aside.
In a small, heavy-bottomed saucepan, melt the butter over medium-low heat.
Stir in the allulose and erythritol-based sweetener. Over medium or medium-low heat (don’t be tempted to turn the heat up higher!), bring the mixture to 310 degrees F, stirring frequently. Once it reaches 310 degrees, immediately remove it from the heat to keep it from burning Note:At first, the mixture will look greasy and separated, then it will turn a golden brown, then it will start foaming with large bubbles when it reaches 310 degrees.
Stir in the peanuts, baking soda, pure vanilla, and sea salt.
Pour the mixture onto the prepared pan and spread it into a thin layer.
Allow to cool completely. Then, transfer it, uncovered, to the freezer for 15 to 30 minutes or until hardened. Break into pieces and serve.
Store in a sealed container or freezer-safe baggie in the freezer for up to 3 months. Eat straight from the freezer.
Notes
I highly recommend using a candy thermometer! If you don't use a thermometer, you run the risk of burning your mixture and having to start over. Stir frequently and remove from heat as soon as it reaches 310 degrees to prevent burning.
If you prefer, you can replace the peanuts with unsalted roasted walnuts or pecans.
Dry-roasted salted peanuts can be substituted. If using the salted variety, omit the sea salt.
I don't recommend substituting the allulose and erythritol. The allulose results in a super smooth candy with no aftertaste. There is just enough erythritol to make the peanut brittle crunchy (instead of chewy) without leaving an aftertaste or making the candy grainy. The combination of the 2 sweeteners is what makes the candy have the perfect taste and texture.