Preheat oven to 325°F (163°C ) and line a baking sheet with parchment paper.
Arrange cookies in a single layer to cover the pan.
36 Biscoff cookies
Cook the toffee: In a saucepan over medium heat, melt the butter and brown sugar, stirring as needed. Allow the mixture to come to a boil, then reduce heat and simmer gently for 2-3 minutes or until temperature reaches 275-285°F (135-141°C) on a candy thermometer. Do not let the temperature go above 300°F (150°C).
¾ cup butter, ¾ cup brown sugar
Melt Biscoff Spread and Add to Toffee: While the sugar mixture is boiling, gently warm the Biscoff spread in the microwave for 20–30 seconds, just until melted and smooth.Once the saucepan is off the heat, slowly whisk in the melted Biscoff until fully combined. Taking the pot off the heat is key — adding Biscoff while the mixture is too hot can cause it to clump.If the mixture looks thick or starts to get a little clumpy, don’t panic. Simply whisk in 1–2 tablespoons of heavy cream (I used 35% heavy whipping cream) and keep whisking until the mixture smooths out again.Troubleshooting (If It Separates)Sometimes the butter can separate — this is normal and totally fixable.Place the pot back on a warm burner with the heat off or on the very lowest setting, then whisk gently until everything comes back together. If you haven’t added the cream yet, add it now — it helps bring the mixture back into a smooth, glossy sauce. 1-2 tbsp heavy cream, 3/4 cup Biscoff spread
Pour the toffee over the cookies and use a silicone spatula to spread evenly. You may need to use your hands to keep the cookies steady while spreading but be careful not to let the hot toffee touch you. Don't worry about it being perfect, it will continue to spread while baking.
Bake in the preheated oven for 5-7 minutes. Remove from overn and sprinkle chocolate chips on top and let sit for a couple of minutes to melt, then spread evenly.
Top with crushed cookies. Chill for 2 hours or overnight in the refrigerator.
4 Biscoff cookies
Break into pieces and enjoy!