Add castor sugar or raw cane sugar, before adding milk. Mix well.
Add apple pieces and mix. Top with thinly sliced apples.
Video
Notes
In Walnut Brownie and Choco Chips Mug Cake I have used jaggery Powder. You can use brown sugar/castor sugar or any other sweetener.In Funfetti and Apple Cinnamon Mug Cake, added raw cane sugar you can add brown sugar/jaggery powder. Color will be a bit dark.In place of Whole Wheat flour you can use all purpose flour(APF).When using APF add little less milk about (3 tbsp)For Vegan Mug Cakes, add plant based milk and oil. Skip butter and dairy milk.