1. Custard powder is not a single thing, so it cannot be said. It is a food additive. It is a mixture of many materials.

2. Custard powder should be regarded as a kind of spice powder or filling thickener. It is used in Western food to make cakes, egg tarts, bread, puddings, stuffings, etc. After adding custard powder, the food will become nice, soft, fragrant and smooth. So in general, custard powder is used to increase flavor, color, crispness and stickiness.