Preheat oven to 175 degrees Celsius and grease two 20cm round cake pans.

Sift together the flour and baking powder in a bowl, then whisk in the ground pistachios and salt.

In a stand mixer fitted with a whisk attachment, beat eggs and sugar on medium-high speed for 5 minutes until ribbon stage is reached.

Reduce mixer speed to low and gradually incorporate the melted butter, milk, vanilla extract, and almond extract.

Gently fold the dry ingredients into the wet mixture in three batches using a silicone spatula to maintain aeration.

Divide the batter equally between the prepared pans and bake for 30-35 minutes until the internal temperature reaches 98 degrees Celsius.

Cool cakes in the pans for 10 minutes, then invert onto a wire rack to cool completely.

Prepare the frosting by whisking mascarpone, pistachio paste, and powdered sugar until homogenous.

Slowly add the chilled heavy cream while whisking on medium-high speed until stiff peaks form, then fold in the melted white chocolate.

Slice the cooled cake layers horizontally if thinner layers are desired, or proceed to stack the two layers with a generous amount of pistachio cream between them.

Apply a crumb coat of cream to the exterior, refrigerate for 20 minutes, then apply the final layer of frosting.

Press crushed pistachios onto the sides or top of the cake for garnish and refrigerate for 2 hours before serving.