To prepare the peanut brittle:

1. First, read through the instructions completely and have your brittle ingredients prepared and close by. Line a large baking sheet with parchment paper and set aside.
2. In a medium heavy-bottomed saucepan, stir to combine the water, sugar, and corn syrup. Turn on medium heat and begin heating the mixture, stirring occasionally, until it comes to a boil. Hook a candy thermometer to the side of the pan and heat the mixture, continuing to stir occasionally, until it comes to 250 degrees Fahrenheit. Add the peanuts and begin stirring with a rubber spatula continuously for about 10 minutes until the mixture reaches 300 degrees Fahrenheit. Immediately remove from the heat and stir in the butter, baking soda, and vanilla. Be careful, as the mixture will eb hot. Pour the hot mixture onto the prepared baking sheet and carefully smooth it into a thin layer quickly. Allow to cool completely prior to storing in an air-tight container at room temperature for up to two days in advance.

To prepare the cookies:

1. Preheat the oven to 350 degrees. Line two pans with parchment paper or silicone baking mats.
2. Melt the butter over medium heat on the stove. Stir regularly and remove the pan from heat immediately once all is melted. Pour into a large mixing bowl and whisk in the peanut butter. Add the brown sugar, sugar, and vanilla extract, stirring to combine. Add the eggs and whisk to incorporate.
3. Add the flour, baking powder, baking soda, and salt to the mix immediately and fold to combine. Don’t waste a lot of time as the mixture will be harder to work with as it sits and cools. Fold in the baking chips and peanut brittle.
4. Scoop tablespoon-sized scoops (I use a medium cookie scoop) of dough on the baking sheets about 2 inches apart. If desired, place some additional peanut brittle into a large plastic bag and use a rolling pin to crush it into a sandy mixture. Roll the dough in your hands to smooth and roll briefly in the crushed brittle to pick up little shards of the candy on the dough. Bake in the preheated oven 10-11 minutes or until the edges are set. Allow to cool briefly before eating!