Preheat the oven to 180°C (356°F).
Combine cake flour, baking powder, sugar, and salt in a bowl and mix well.
Add cold butter, cut into small pieces, and mix by hand until it resembles coarse crumbs.
Add milk and heavy cream, and mix until dough forms into one mass.
Roughly chop the pistachios and mix them into the dough.
Flatten the dough to about 2-3 cm thick and cut into desired shapes.
Place on a baking sheet and brush the tops with egg wash or cream.
Bake in the preheated oven for 20-25 minutes until done.