Add steel cut oats, almond flour, flour or gluten free baking mix, eggs, baking soda, milk, brown sugar, stevia, salt, cinnamon and lemon juice to the blender and blend until smooth.
Shred apple.
Place muffin liners into a muffin tin.
Pour the batter into each muffin tin and add ~ 2 teaspoons shredded apple on top of the batter. Sprinkle with a little more cinnamon.