1stick (4 ounces) unsalted butter, at room temperature
1/4cuppacked light brown sugar
1cupall-purpose flour
Pinchsalt
For the filling:
3large eggs
1 1/4cupspacked light brown sugar
1/2cupBiscoff spread, or other cookie spread
1/2cupall-purpose flour
Instructions
For the crust:
Preheat the oven to 350°F. Line an 8x8-inch baking pan with parchment paper or foil and spray with nonstick cooking spray.
In a large bowl, use an electric mixer to combine the butter, sugar, flour, and salt until mixture is well combined and moistened. Press the mixture evenly into the prepared baking dish. Bake for 15 minutes, or until the edges are golden brown. Let cool.
For the filling:
In a large bowl, use an electric mixer to combine the eggs, sugar, Biscoff, and flour until well combined and smooth.
Pour the mixture over the cooled crust and bake for 30 minutes, or until the middle is just set. Let cool completely on a wire rack before cutting into 16 bars to serve. Bars can be made up to 2 days ahead of time and stored at room temperature in an airtight container.