Preheat the oven to 180℃ and line the 2lb loaf tin with non-stick baking paper
In a large bowl, whisk together the flour, custard/cornflour, bicarbonate of soda and salt.
Stir in the brown sugar
Melt the margarine and our into the flour mix, along with the milk, yoghurt and syrup. Stir well to form a lovely smooth cake batter
Pour into the lined tin and level off the top
If you want to get a neat crack down the middle, dip a round ended knife into melted margarine and use it to drawn a line down the middle of the cake
If using, sprinkle the pearl sugar over the top
Bake for around 30 minutes, until risen and golden and a knife comes out clean
Remove from the tin and let fully cool on a wire rack
If you want to make an extra glossy cake, brush with an extra tbsp of syrup whilst it is still warm
