Prep: Heat oven to 350°F (175°C). Line two baking sheets with parchment paper.
Crush cookies: Finely crush about 1 cup of Biscoff cookies. Set aside.
Cream butter and sugars: Beat 1/2 cup softened unsalted butter with 1/2 cup brown sugar and 1/4 cup granulated sugar until fluffy, 2–3 minutes.
Add wet ingredients: Mix in 1 large egg, 1 teaspoon vanilla, and 1/3 cup Biscoff cookie butter until smooth.
Whisk dry: In a separate bowl, whisk 1 1/4 cups all-purpose flour, 1/2 teaspoon baking soda, 1/4 teaspoon baking powder, 1/4 teaspoon salt, and 1/2 teaspoon cinnamon.
Combine: Add dry ingredients to the wet and mix just until combined.
Fold in the crushed Biscoff cookies and 1/2 cup white chocolate chips if you like.
Scoop: Use a 1.5-tablespoon scoop to portion dough onto trays, leaving space to spread. Chill the scooped dough for 15 minutes for thicker cookies.
Bake: Bake 9–11 minutes, until edges are set and centers look slightly underdone. Cool on the tray 5 minutes, then transfer to a rack.
Prep: Heat oven to 350°F (175°C).
Line an 8-inch square pan with parchment, leaving overhang for easy lifting.
Melt and mix: Melt 1/2 cup unsalted butter. Whisk in 1/2 cup brown sugar and 1/3 cup granulated sugar. Add 1 large egg, 1 teaspoon vanilla, and 1/3 cup Biscoff cookie butter; whisk until glossy.
Dry ingredients: Stir in 1 cup all-purpose flour, 1/2 teaspoon baking powder, 1/4 teaspoon salt, and a pinch of cinnamon.
Fold-ins: Add 1/2 cup chopped Biscoff cookies and 1/2 cup white or dark chocolate chips.
Bake: Spread batter evenly.
Bake 20–24 minutes, until the top is set and a toothpick comes out with moist crumbs. Don’t overbake.
Finish: Cool completely, then drizzle 2–3 tablespoons warmed Biscoff cookie butter on top. Slice into squares.
Crust: Finely crush 2 cups Biscoff cookies.
Mix with 6 tablespoons melted butter and a pinch of salt. Press into a 9-inch springform pan. Chill 15 minutes.
Filling: Beat 16 ounces cream cheese (softened) with 1/2 cup powdered sugar and 1 teaspoon vanilla until smooth.
Beat in 1/2 cup Biscoff cookie butter.
Whip cream: In a separate bowl, whip 1 cup cold heavy cream to stiff peaks. Gently fold into the cream cheese mixture until combined.
Set: Spread filling over crust. Chill at least 6 hours, preferably overnight.
Topping: Warm 1/3 cup Biscoff cookie butter until pourable.
Drizzle over the cheesecake and sprinkle with crushed cookies before serving.