Melt 100g of white chocolate in a heatproof bowl over a simmering pot of water, then mix in 100ml of hot heavy cream and 2 tablespoons of Biscoff spread until smooth. Cool and refrigerate for 1-2 hours.

In a food processor, combine 120g of almond flour, 160g of powdered sugar, and 50g of finely crushed Biscoff cookies. Pulse until smooth and sift into a bowl.

Whip 100g of egg whites with an electric mixer until foamy. Gradually add 100g of granulated sugar and whip until stiff peaks form, about 5-7 minutes.

Gently fold the dry ingredients into the meringue until combined and the batter flows in thick ribbons.

Transfer the batter to a piping bag and pipe 2-inch rounds on a baking sheet. Tap the sheet to release air bubbles.

Let the shells rest for 30-45 minutes until a skin forms and they are no longer tacky.

Preheat the oven to 145°C (290°F). Bake the macarons for 14-15 minutes. Let them cool before removing from the sheet.

Once cooled, pipe ganache onto half of the macaron shells, add Biscoff spread on top, and sandwich with the remaining shells.