Butter a large baking sheet very well then set aside.

Add sugar, water, corn syrup and salt to a large, heavy-bottomed saucepan—you want one that’s large enough to allow the mixture to expand by at least 5 times. Place it over medium-high heat and bring to a boil, stirring frequently with a wooden spoon until the sugar has dissolved. Place a candy thermometer into the sugar mixture and allow the syrup to heat until it hits 290–295 degrees.

While the syrup is heating, stir together the vanilla and baking soda in a small bowl then measure out the peanut butter and place in a separate bowl. Don’t skip this step! These ingredients need to be added while the sugar syrup is very hot, so you will not have time to measure ingredients or dig peanut butter out of the jar.

When the syrup reaches 290–295 degrees, remove from heat and stir in the vanilla/baking soda mixture. The mixture will bubble furiously, but stir constantly and mix thoroughly, being careful not to be burned by rising steam. Working quickly but carefully, add the peanut butter to the hot syrup and stir to completely combine. Immediately transfer the mixture to the baking sheet then spread or press it until ¼" thick. Set aside to cool.

After the candy has cooled to room temperature, melt the bag of chocolate chips in the microwave. Heat the chocolate 30 seconds, stir, then continue heating in 15-second intervals, stirring after each, until the chocolate is 80%–90% melted. Remove from microwave and continue stirring until the remaining chocolate is melted.

Spread the melted chocolate in a thin layer over the top of the candy then set aside to allow the chocolate to set. Slice into bars and serve chilled or at room temperature to an awestruck audience. Enjoy!