Melt 100g of white chocolate in a heatproof bowl over simmering water. Stir until smooth. Remove from heat and whisk in 50ml of hot heavy cream and 75g of Biscoff spread until combined. Cool at room temperature, then refrigerate for 30 minutes until thick enough to pipe.

In a food processor, pulse 125g of almond flour, 200g of powdered sugar, and 50g of crushed Biscoff cookies until finely blended. Sift into a large bowl to remove lumps.

Beat 100g of egg whites on medium speed until foamy. Gradually add 100g of granulated sugar and whip until firm peaks form, about 5-7 minutes.

Gently fold the sifted dry ingredients into the whipped egg whites until it reaches the 'ribbon' stage.

Fill a piping bag with the batter and pipe 3 cm circles onto baking sheets lined with parchment paper.

Tap each baking sheet against the countertop to release air bubbles.

Allow piped macarons to rest at room temperature for 30 to 45 minutes until they form a dry skin.

Preheat the oven to 145°C (290°F) and bake for 14 to 15 minutes.

Once cooled, pipe the ganache onto one macaron shell, add a dot of Biscoff spread, and sandwich with another shell.