01 -
Line an 8x8 inch metal baking pan with parchment paper, pressing firmly into corners.
02 -
Combine crushed Biscoff cookies with melted butter until evenly moistened, then press evenly into the bottom of the prepared pan.
03 -
In a large bowl, beat eggs, granulated sugar, and brown sugar on high speed for one minute until light and creamy.
04 -
Mix in melted cooled butter and vanilla extract on medium speed until glossy and fully combined.
05 -
Sift flour, cocoa powder, and baking powder over wet mixture to prevent lumps.
06 -
Gently fold dry ingredients into wet mixture until just a few streaks remain, avoiding overmixing for a tender texture.
07 -
Pour batter over cookie crust in the pan, spreading evenly without disturbing the crust.
08 -
Dollop warmed Biscoff spread atop batter and swirl gently using a butter knife for marbled effect.
09 -
Bake at 350°F (177°C) for 22 to 25 minutes, until edges are set, top is shiny, and a toothpick inserted comes out with moist crumbs.
10 -
Allow to cool fully in the pan for at least one hour before slicing for clean, neat bars.