Chop 200g of white chocolate and place it in a heatproof bowl. Heat 100ml of heavy cream until simmering, then pour over chocolate. Stir in 2 tablespoons of Biscoff spread until smooth. Refrigerate for 1 hour.

Combine 100g of almond flour, 100g of powdered sugar, and 60g of crushed Biscoff cookies in a food processor. Pulse for 30 seconds and sift into a bowl.

Add 100g of egg whites to a mixing bowl and whip on medium speed for 2 minutes. Gradually add 100g of granulated sugar and whip until firm, glossy peaks form, about 5 minutes.

Gently fold the dry mixture into the whipped egg whites about 30 times until combined.

Transfer batter to a piping bag and pipe circles on a lined baking sheet, about 1.5 inches in diameter.

Tap the tray on the counter to release air bubbles and smooth the tops of the macarons.

Allow the macarons to rest at room temperature for 30–45 minutes until they form a shiny skin.

Preheat the oven to 145°C (290°F) and bake the macarons for 14–15 minutes, rotating halfway through.

Cool the macarons completely, then whip the ganache until fluffy. Pipe onto one shell, add Biscoff spread, and sandwich with another shell.

Let assembled macarons rest in the fridge for at least 24 hours before serving.