Preheat your oven to 300°F (150°C) and line two baking sheets with parchment paper, drawing circles as guides.

In a bowl, whisk together powdered sugar, finely ground pistachios, and cake flour until well combined.

In another bowl, whip room-temperature egg whites with cream of tartar and salt until soft peaks form.

Gradually add granulated sugar while continuing to whip until stiff peaks form, then gently fold in the dry ingredients.

Pipe the meringue onto the parchment circles and bake for 30 minutes, then reduce to 250°F (120°C) for an additional 30-45 minutes until golden.

Allow the meringue layers to cool completely.

In a saucepan, combine sugar and water, cooking over medium heat until it reaches 240°F (115°C) for the buttercream.

Whip the egg yolks until fluffy and light in color; slowly drizzle the syrup into the yolks while whisking.

Gradually add unsalted butter, mixing until smooth; then incorporate pistachio paste and vanilla extract.

For raspberry coulis, cook raspberries with sugar and lemon juice until syrupy, about 10-15 minutes; strain if desired.

Assemble the cake by layering the meringue, piping buttercream and adding coulis between layers; frost with remaining buttercream.

Garnish with chopped pistachios and fresh raspberries; chill for 30 minutes before slicing.