First, peel and core the apples, then cube them. Transfer to a bowl and add in the cinnamon and mix thoroughly till all the apple cubes are coated in cinnamon.
Next, mix together all the dry ingredients in a separate large mixing bowl. In another bowl or measuring cup, mix together all the wet ingredients and whisk thoroughly to combine.
Then in the bowl of the dry ingredients, add in the wet ingredients and mix with a spatula just until well combined, making sure there are no lumps. After, fold in the apples just until well incorporated.
Let the muffin batter rest for a while but in the meantime, grease a muffin pan with butter, I like to grease the entire pan, so when the muffins puff up, they don't stick to the edges of the pan. Pre heat your oven to 300 degrees fahrenheit for about 7 - 10 minutes to get the oven hot enough.
While you wait for your oven to preheat, fill your muffin pan with the muffin batter.
Bake the muffins in the preheated oven on the middle rack for about 30 minutes, till a toothpick inserted comes out clean and the muffins brown. Baking time may vary. Let cool for about 5 minutes in the pan and transfer to a cooling rack to cool completely or enjoy them warm. This muffin batter keeps well in the fridge for up to 3 days, baking instructions stay the same.
If making a mug cake, pour in a medium sized mug about 5 heaped tbsp of the muffin batter and microwave for about 1 minute 30 secs, if a toothpick inserted doesn't come out clean, microwave another 30 seconds but using 10 second intervals just in case they cook faster. Over microwaving will cause your muffin to be rubbery. Happy baking!
