Preheat the oven to 325ºF. Line a 9x13” baking dish with foil or parchment paper, leaving a 1-inch overhang. Spray with nonstick cooking spray.
Place both sugars in the bowl of a mixer. Set aside.
In a medium saucepan, melt the chocolate chips and the butter together. Once melted and combined, pour the melted chocolate mixture in with the sugars. Mix on low to combine, then add the eggs, vanilla and salt and mix.
Add 1/2 cup of the flour, then mix to combine. Add the remaining cup of flour and mix just until combined. Pour the batter into the prepared pan.
Melt the Biscoff spread in a microwave safe bowl for 15-30 seconds. Pour the spread over the brownie batter in 3 long strips lenthwise. Use a butter knife to swirl the spread, dragging it the opposite direction.
Bake the brownies for 35-40 minutes, or until a toothpick inserted in the center comes out clean.
Notes
from The Biscoff Cookie and Spread CookbookNutrition information provided as an estimate only. Various brands and products can change the counts. Any nutritional information should be used as a general guide.