1. Preheat oven to 350° F. Grease the bottom and sides of a 9 x 13-inch baking dish and line with a piece of parchment that overhangs the two opposite long sides (so you can hold onto the paper to lift them out later).
2. Prepare brownie mix as directed on package. If you are adding optional mix ins, stir them in now. Pour into prepared baking dish.
3. Place peanut butter in a microwave safe bowl and heat in 30 second bursts until it is soft (this usually takes about 60 seconds). Alternatively, you can thin the peanut butter over a double boiler.
4. Using a teaspoon, drop a spoon’s worth of the peanut butter at a time all over the brownie mix in the baking dish, until all of the peanut butter is used up. Drag a knife through the peanut butter to swirl it through the mix.
5. Bake the brownies for 25-30 minutes, or until a toothpick inserted in the middle comes out mostly clean. Cool for 30-40 minutes on the counter and then transfer to the refrigerator to cool completely (about an hour more). Once cool, run a knife along the short edges of the brownies where there is no parchment. Use the parchment to carefully lift the brownies out of the pan and transfer to a cutting board. Use a chef’s knife to cut into 16 servings. Brownies can be stored in an airtight container for several days at room temperature.

Note: Natural Grocers Brand Bulk ingredients are packaged in a plant that processes gluten.