Pistachio and rose ice cream cake

Method

1. Heat the oven to 180°C/160°C fan/gas 4. Put all the cake ingredients in a large bowl. Using an electric hand mixer, beat until smooth and just combined. Pour into the tin and bake for 20-25 minutes until risen, golden and springy to the touch.
2. Meanwhile, make the syrup. Put the 2 tbsp sugar in a pan with 3 tbsp water and heat gently until dissolved. Turn up the heat and cook for a few minutes until the mixture turns syrupy, then remove from the heat and stir in the rosewater.
3. Once the cake has baked, remove from the oven and use a cocktail stick to poke holes all over the top. Using a pastry brush, brush the syrup all over. Leave to cool completely in the cake tin, then turn out onto a chopping board and use a serrated bread knife to cut the cake in half horizontally to make 2 layers. Take the ice cream out of the freezer and leave to soften for 5-10 minutes.
4. Put one layer of cake back in the lined cake tin, then spoon in the softened ice cream, levelling and smoothing it out as you go. Add the second layer of cake to make a lid, cover with a couple of sheets of cling film, then freeze for 1-2 hours until solid (see make ahead).
5. Once frozen solid, transfer the ice cream cake to a serving plate. Pour the melted chocolate over the top and encourage it to drip down the sides by tilting the plate slightly. Return to the freezer until set (see make ahead). To serve, take the cake out of the freezer for 10 minutes to soften, then decorate with a few rose petals (see tips).