Preheat the oven to 180C/350F and spray 8 holes of a muffin tin with cooking spray.
Place the oats, sugar, baking powder, cinnamon, salt and raisins into a large bowl and stir briefly to combine.
Add in the chunks of apple and stir to combine.
Add in the milk, egg and vanilla extract and stir until everything is well combined and coated in the liquid.
Place 3tbsp of mixture into each hole of your muffin tin and place in the oven for 12-15 minutes, until slightly risen, golden on top and they look set.
Leave to cool in the pan for at least 10 minutes before digging in. You can also let them cool completely - they are delicious warm and cool!
Apple and Raisin Oatmeal Cups will keep in an airtight container, in the fridge for a week and at room temperature for 4 days. Serve at room temperature or warmed in the microwave.