Preheat your oven to 350℉.
Line a 5"x*' loaf pan with parchment paper. See recipe notes on size of pan.
Slice the apples thinly, preferably using a mandolin.
In a clean bowl, add the baking soda, salt, and almond flour and whisk to blend.
Add the eggs, milk, maple syrup, vanilla extract, and butter to the blended dry ingredients and blend well with a spatula or your hands until all the apple slices are coated with batter.
Layer the apples in the baking pan in small batches, getting each layer relatively even and the corners covered. Add an extra batter on top of the apples.
Bake for 50 minutes or until browned on top and firm to touch.
Remove the cake from the pan and cool for at least 20 minutes.
Store leftovers in the refrigerator for a week or so.
