Choose a new cookbook worth up to £28 when you subscribe to our magazine.
Heat oven to 170C/150C fan/gas 3 1/2 and butter and line the base of a 23cm square cake tin. In a bowl, cover the dates and bicarb with boiling water and leave to sit for 10 mins to soften, then drain and blitz to a rough paste in a food processor.
Using an electric hand whisk or tabletop mixer, cream the butter with the sugar until golden and fluffy, then gradually beat in the eggs. Add the date paste, flour, treacle, ginger, stem ginger, syrup, parsnips and a pinch of salt. Mix to combine, and pour into the tin. Bake for 30 mins until a skewer inserted into the centre comes out with only a few crumbs attached.
Meanwhile, make the toffee sauce. Put the butter, sugar and cream in a saucepan with 1 tsp flaky sea salt over a gentle heat. Cook, stirring, until the sugar has dissolved, the butter has melted and the sauce has thickened and is toffee coloured. Remove the cake from the tin and slice. Serve with the sauce and vanilla ice cream.