1tablespoonmaple syrupto taste (or sub any other sweetener)
4tablespoonsplain flour (or sub rice flour if gluten-free or your favourite gluten-free flour blend)
1/4teaspoon baking powder(ensure gluten-free if necessary)
Mix together the coconut oil, milk, lemon juice and maple syrup in a mug/small bowl
Add the flour and baking powder, and mix well until it has the consistency of cake batter - add a splash more milk if it's looking too dry
Add the blueberries and carefully stir through
Microwave for 1 minute, or until the cake has risen and cooked through - test with a skewer or fork and make sure it comes out clean. Microwave in 10-second bursts until you get your desired result
You can also make this in the oven instead of the microwave. Just bake at 180 degrees Celsius (350 degrees Fahrenheit) for around 15 minutes, or until risen and an inserted skewer or fork comes out clean.