Preheat oven to 450°F/230°C and then find yourself an oven safe dish that’s about 4 inches in diameter. You can also use a large muffin tin for the baking portion, but start with a microwave safe bowl until you get past step #6 below.
Chop your apple into roughly 1-inch chunks and place in the baking dish.
Add your sweetener of choice. I typically use coconut sugar but granulated white sugar or brown sugar will work, as well. If you choose to use a calorie-free sweetener such as monk fruit or stevia, you may want to add only ½ the amount called for in the recipe, as many calorie-free sweeteners are much sweeter than coconut, white or brown sugar.
Next, add the lemon juice. If you don’t have any fresh lemons handy, the bottled type of lemon juice will work just fine.
Dust the top of your apple mixture with ground cinnamon.
Microwave your apple mixture on high for one minute. If you’re not a fan of microwaving or if perhaps you don’t even own one - no biggie! Just add 3 - 5 minutes to the oven cooking time below. *If you’re using a muffin tin, transfer the apple mixture over to that tin once this step is complete.
In a small bowl, add the oats, butter, cinnamon, sugar and nuts (if using) and mix with your fingers until all dry ingredients are well incorporated.
Sprinkle this lovely oatmeal concoction evenly over the top of your apple mixture.
Place your dish on a baking sheet and place on the top rack in the oven. Bake for approximately 6 - 10 minutes or until the highest peaks of the oatmeal start to turn a light brown color. Two other indicators that the dessert is done baking is the glorious smell that suddenly permeates the kitchen, plus, the juices from the apples start to bubble.
If you’re using a muffin tin, carefully spoon the dessert out into the serving vessel of your choice.As a note: Be careful when handling after baking, as the dish or muffin tin will be very hot!Serve with dairy-free vanilla ice cream, if desired.