Preheat oven to 350ºF.  Grease and flour a 9"x 2" round cake pan.

In a blender or food processor, process pistachios until finely ground and fluffy (but not past that point or you might make butter!).  Transfer to a bowl and whisk in flour, baking powder and salt.

Beat butter and 1/2 cup of the sugar in a standing mixer until light and fluffy, about 2 minutes, pausing once to scrape down sides of bowl. Beat in eggs one at a time, beating well after each. Beat in almond extract. With mixer speed on low, gradually add the flour mixture, beating only until combined.

Using a wooden spoon or spatula, gently fold in one package of the raspberries. Spread the batter into prepared pan, smoothing it out evenly.  Drop a handful of remaining raspberries on top of the batter, then keep the rest for serving.  Sprinkle with remaining tablespoon of sugar.

Bake in centre of the oven for 40-50 minutes, rotating pan halfway through, until golden brown and springy to touch when pressed gently in the centre.

Transfer to a wire rack to cool.  To serve, dust with confectioners' sugar (optional) and sprinkle with a few chopped pistachios. Spoon into bowls and serve with whipped cream and reserved fresh raspberries.