Step 1

Grease a 25 cm round cake pan.

Step 2

Place sweet potato in a pan with a little water.

Step 3

Boil until tender, then drain and cool. Mash sweet potato with custard.

Step 4

Coat sultanas with 1 tablespoon of the flour, and set aside.

Step 5

Beat butter, sugar and honey in a large bowl with an electric mixer until light and fluffy.

Step 6

Beat in eggs, one at a time, until combined.

Step 7

Lower the mixing speed, beat in sweet potato mixture, then gradually beat in flour until combined.

Step 8

Use a wooden spoon to stir in sultanas, then pour mixture into prepared pan.

Step 9

Bake at 150C for about 1 hour 40 minutes or until a skewer inserted in the centre comes out clean.

Step 10

Serve cake warm or cold, dusted with sifted icing sugar.