Oreo Ganache

1. Melt the white chocolate in the microwave, heating in 20-30 second intervals and stirring in between, until smooth and fully melted.
2. Heat the heavy cream in a small saucepan over medium heat, until warm but not boiling.
3. Pour the warm cream over the melted chocolate and finely ground Oreo cookies (without the cream), and stir until smooth and well combined.
4. Let the ganache set at room temperature, or refrigerate for about 1 hour until it thickens and becomes easier to use.

Oreo Macarons

1. Blend the almond flour, powdered sugar, and Oreo cookies (without the cream) in a food processor until you get a fine, homogeneous powder.
2. In the bowl of your stand mixer, whip the egg whites until foamy. While the mixer is on low-medium 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 whipping until stiff peaks form with a bird's beak.
3. Gently fold the dry ingredient mixture into the meringue all at once, using a flexible spatula to avoid deflating the meringue. Mix until you achieve a smooth batter that forms a ribbon when you lift the spatula.
4. Using a piping bag, pipe small dollops of batter onto a baking sheet lined with parchment paper.
5. Let the macarons rest for 30-45 minutes until they form a crust.

Baking

1. Preheat your oven to 150°C (300°F).
2. Bake the macarons for about 14-15 minutes, then let them cool completely on a wire rack.
3. Once the shells are cooled, pipe the Oreo white chocolate ganache onto them.
4. Sandwich the macaron shells together to form the macarons.