Preheat oven to 180°C (160°C fan-forced). Grease the base and sides of a 6cm-deep, 20cm x 30cm (base measurement) cake pan and line with baking paper. Place the pistachios in a food processor and process until finely ground.
Step 2
Use an electric mixer to beat the butter and sugar in a large bowl until pale and creamy. Add the eggs, one at a time, beating well after each addition. Add the combined flour, ground pistachio and sour cream and stir to combine. Spoon into prepared pan and smooth the surface. Bake for 50 mins-1 hour or until a skewer inserted in the centre comes out clean. Set aside for 15 mins to cool, then turn onto a wire rack to cool completely.
Step 3
Meanwhile, combine strawberry, sugar and 1 cup (250ml) water in a saucepan over medium-low heat. Cook, stirring, for 2 mins or until sugar dissolves. Increase heat to medium and bring to a simmer. Cook for 5 mins or until syrup thickens slightly.
Step 4
Use an electric mixer to whisk the mascarpone, cream, icing sugar and pistachio spread in a large bowl until firm peaks form.
Step 5
Use a large serrated knife to trim top of cake to level. Cut the cake in half crossways. Place cake base in pan and brush with half the strawberry syrup. Spread one-third of the pistachio mascarpone over the strawberry syrup. Arrange two-thirds of the strawberries evenly over pistachio mascarpone. Spoon over half the remaining pistachio mascarpone. Brush top and cut-side of cake top with the remaining strawberry syrup. Place, cut-side down, over mascarpone mixture.
Step 6
Chill cake in the fridge for 4 hours or overnight to set.
Step 7
Turn the cake onto a serving platter. Spread remaining pistachio mascarpone over the top and drizzle with warm pistachio spread. Decorate with remaining strawberries. Sprinkle with chopped pistachio to serve.