Make the macaron shells

1. Mix the powdered sugar and almond flour, then sift or blend in a food processor.
2. Add the first egg white and vanilla and mix until you have a thick paste.
3. Heat the sugar and water in a saucepan until the syrup reaches 230°F / 110°C.
4. When the syrup approaches temperature, whip the second egg white in a stand mixer until foamy.
5. At 244°F / 118°C, drizzle the syrup over the egg white while mixing on low, then whip to stiff, glossy meringue.
6. Loosen the almond paste with a small amount of meringue, then fold in the rest until the batter flows in a ribbon.
7. Preheat oven to 320°F / 160°C and line baking sheets.
8. Pipe small rounds, tap the tray to release air bubbles, and bake 12–13 minutes one tray at a time.
9. Let the shells cool completely.

Make the vanilla ganache

1. Heat the cream with the scraped vanilla bean.
2. Pour the hot cream over the chopped white chocolate and mix until smooth.
3. Cover and chill for 3 hours, then whip 1–2 minutes until thick and creamy.
4. Pipe the ganache onto one shell and close with a matching shell.
5. Chill the filled macarons at least 1 hour before serving.