Preheat the oven to 350°F. Line an 8x8-inch baking pan with parchment paper. Chop up the peanut butter cups. Add them to a mixing bowl and set aside.
In a large mixing bowl, add the cane sugar, canola oil, cocoa powder, and dark chocolate. Pour the boiling water directly on top of the chocolate.
Mix with a hand mixer on low to medium speed on until combined and the chocolate has completely melted and there are no chunks.
Add the egg, flour, vanilla bean, baking powder, sand salt in that order. Mix on low until combined, don’t over mix.
Mix on low until combined into a smooth brownie batter.
Add the chopped peanut butter cups into the brownie batter. You can reserve some for the top, if you want, but that’s totally optional.
Fold together the chopped peanut butter cups to combine into the brownie batter.
Transfer the batter to the prepared baking pan and spread it out evenly. Add reserved chopped peanut butter cups on top, if you want.
Bake for 25 minutes to 30 minutes, or until a toothpick inserted in the center comes out clean.
Allow to cool completely in the baking pan and then cut into 16 squares.