Preheat the oven to 180°C.
Place the eggs and sugar in a large bowl, and beat together with an electric mixer on high speed for about 5 minutes. Reduce the speed and slowly pour in the vegetable oil.
Tip in the flour, semolina, baking powder and salt, and mix well until the mixture comes together. Fold in the ground pistachios and lemon zest.
Pour the cake mixture into a greased 24cm springform tin and bake in the oven for 30-35 minutes.
Meanwhile, make the syrup by stirring the honey, water and lemon juice in a saucepan and placing over a high heat. Leave the syrup to boil and reduce by half, which takes about 10 minutes.
Use a skewer to poke deep holes in the cake while it is still hot. Drizzle half of the syrup evenly over the top, allowing it to be absorbed, then pour over the remaining syrup. Leave to cool completely, then sprinkle with the chopped pistachios.
Serve with a dollop of mascarpone cream.
Homemade by Clodagh McKenna, published by Kyle Cathie: With a strong focus on using local produce and eating together, Clodagh McKenna's new cookbook, Homemade brings together recipes and ideas gathered from years of travelling and taking notes. Order the book online.