Step 1

Preheat oven to 160C. Process chocolate and pistachios in a food processor until coarse crumbs form, set aside. Beat butter and sugar in an electric mixer until light and fluffy (2-3 minutes). Add eggs one at a time, beating until well combined, then stir in flour and baking powder. Stir through pistachio and chocolate mixture, then pear, pour into a 22cm-diameter springform cake tin greased and lined with baking paper. Bake until an inserted skewer withdraws clean (30-40 minutes), cool in tin for 10 minutes, turn out and cool to room temperature on a wire rack.

Step 2

Meanwhile, for chocolate ganache, place chocolate in a heatproof bowl and set aside. Heat cream in a saucepan over medium heat to just below boiling, add to chocolate, stand until chocolate melts (3-5 minutes), then stir until smooth, set aside until slightly thickened (5-10 minutes). Smooth over top and sides of cake, scatter with pistachios, set aside to set (20-30 minutes), then serve. Cake will keep, stored in an airtighter container, for 3 days.