1. Preheat the oven to 160C fan-forced (180C conventional) and line a small loaf tin (about 1kg capacity, roughly 20cm x 10cm) with baking paper.

2. Sift together the flour, bicarbonate of soda, baking powder, cinnamon, ginger and salt in a medium bowl and set aside. In a separate large bowl, whisk the eggs and sugars together until combined, then add the oil and continue whisking until creamy.

3. Add the sifted dry ingredients to the large bowl in three batches, mixing lightly with a rubber spatula until almost combined but not quite (there should still be flour visible), then fold in the vanilla, parsnip, apple and lime zest. Mix until just incorporated, then scrape the mixture into the prepared loaf tin.

4. Bake for about 60 minutes, or until a skewer inserted into the middle comes out clean. Remove from the oven and rest on a cake rack for 30 minutes before lifting onto a cake plate to cool completely.

5. While the loaf is baking, prepare the lime icing and garnish. To "fillet" the lime, trim the tops and bottoms of the limes, then stand one of the cut ends on the chopping board. Following the shape of the lime, use a very sharp small knife to slice off the peel and white pith from top to bottom, removing just enough skin to expose the flesh underneath. Trim off any remaining white pith.

6. Holding the lime over a bowl to catch the juices, cut along on either side of each of the membranes to remove the "fillets" and drop them into the bowl. Repeat with the second lime, then strain to separate the fillets from the juice. Measure out 40ml of juice and whisk into the icing sugar to make a smooth icing.

7. When the loaf has cooled completely, drizzle over the icing and allow to settle for a few minutes; it won't set hard, but will form a glaze. Just before serving, lay the lime fillets attractively down the centre of the loaf.

If you like this recipe try my burnt butter parsnip cake with white chocolate cream.

Brain Food: Can I use parsnip instead of carrot in a cake?