Combine the powdered sugar and almond flour, then blend in a food processor for a few seconds to make the mixture finer.

Place the egg whites in a stand mixer bowl. Beat on low speed, gradually increasing the speed. When the mixture becomes foamy, add the granulated sugar in three additions. Beat until you get a smooth, glossy meringue.

Add the mixture from step 1 and the food coloring to the meringue. Gently fold together with a spatula until combined.

Transfer the batter to a piping bag fitted with a plain 8 mm tip. Pipe rounds onto a baking sheet lined with parchment paper.

Let the shells sit for 30 minutes to form a skin, then tap the tray to release any air bubbles. Bake in a preheated oven at 275°F (135°C) for 7 minutes, then rotate the tray and bake for another 7 minutes.

Remove from the oven and let the shells cool completely before removing them from the baking sheet.

Bring the heavy cream to a boil. Chop the white chocolate into small pieces. Pour the hot cream over the white chocolate and stir with a spatula until smooth. Add the raspberry purée and mix well. Cover with plastic wrap directly on the surface and refrigerate overnight.

Whip the ganache with a mixer until it becomes light and fluffy.

Transfer the ganache to a piping bag fitted with a tip, pipe onto half of the macaron shells, then top with the remaining shells. Refrigerate the macarons for a few hours before serving.