baking mixes (e.g. biscuit, cake, cookie, cupcake, fairy cake) that contain separately packaged taxable foods, such as edible cake decorations, within the box or packet

ATO Reference

#1839

ATO Notes

Where a mix of GST-free and taxable separately packaged goods is packed and sold together the items are taxed individually as a mixed supply. This is not a combination of foods, one of which is taxable. This is because additional ingredients, such as eggs and milk, and further steps are required (refer to Example 2 in GSTD 2024/1).