Using a hand mixer or a stand mixer with the paddle attachment, beat together the peanut butter, brown sugar, egg and vanilla until the sugar is fully incorporated and the mixture is not grainy (this will take 5-8 minutes probably). Scrape sides of the bowl as needed. This mixture will seem oily.
Beat in the baking soda for about a minute, until fully combined.
Mix/beat in the toffee/chocolate chips.
Using a medium/2 in. cookie scoop, scoop 2-3 tbsp. mounds of cookie dough and place on a large plate or cookie sheet. Cover with plastic wrap and refrigerate for at least 2 hours, up to 5 days.
When ready to bake, preheat oven to 350 degrees and prepare baking sheet with parchment paper or silicone baking mat. Place chilled cookie dough mounds on sheet, spacing at least 2 inches apart (I had about 8 cookies on a sheet, and did 2 batches--keep the rest of the cookie dough balls in the refrigerator until you are ready to bake them).
Bake for 8 minutes, until just barely set. May seem a little underbaked but they will firm up as they cool. Cool on sheet for 5-10 minutes before transferring to a wire rack to complete cooling.
Store leftover cookies in an airtight container for up to 1 week at room temperature or you can freeze cookies for up to 4 months. (You can also freeze unbaked cookie dough for up to 4 months).
Instant happiness right there. Fresh outta the oven.