Biscoff Ganache

1. Melt the white chocolate in the microwave by heating in 20-30 second intervals, stirring between each, until completely melted and smooth.
2. Heat the heavy cream in a small saucepan over medium heat until it is warm, but do not bring it to a boil.
3. Pour the warm cream over the melted chocolate along with the cookie butter spread and mix until smooth and well combined.
4. Cover with plastic wrap directly on the surface of the ganache and let it set at room temperature or place it in the fridge for about 1 hour to thicken and become easier to use.

Biscoff macarons shells

1. Mix the almond flour, powdered sugar, and biscoff cookie crumbs in a food processor until you get a fine, homogeneous powder.
2. In the bowl of your stand mixer, whisk the egg whites until foamy. While the mixer is running at medium-low speed, add the granulated sugar one tablespoon at a time, every 30 seconds. Once all the sugar is incorporated, increase the speed to medium-high and continue whisking until stiff peaks form (add food coloring here if you want a darker shade).
3. Gently fold in the dry ingredients all at once into the meringue, using a spatula to avoid deflating the mixture. Mix until you get a smooth batter that forms a ribbon when you lift the spatula.
4. Using a piping bag, pipe small mounds of the batter onto a baking sheet lined with parchment paper.
5. Let the macaron shells dry (or "crust") for 30 to 45 minutes before baking.

Baking

1. Preheat your oven to 300°F (150°C).
2. Bake the macarons for about 14 to 15 minutes, then let them cool completely on a wire rack.
3. Once the shells are completely cooled, fill them with the white chocolate biscoff ganache add some biscoff cookie butter spread on the center with a piping bag.
4. Assemble the shells to make the macarons.