Heat oven to 350°F with the rack in the middle. Lightly grease the sides and bottom of a 10-inch non-stick bundt pan with some ghee, coconut oil, or avocado oil.
Use the large holes of a grater or food processor to shred half of the apples and use a sharp knife to thinly chop the other half into small thin rectangles, about the size of your thumbnail.
Place the apples in a bowl and toss with the apple cider vinegar. Set aside.
In medium bowl, whisk together flours, cinnamon, baking soda, and salt. Set aside.
Plop the softened ghee (or coconut oil) and maple sugar (or coconut sugar) in the bowl of a stand mixer or in a large bowl if you are using a hand mixer.
Use the paddle attachment to blend the mixture on medium-high speed for 3 to 5 minutes or until lighter in color and fluffy.
Scrape down the sides of the bowl and add the eggs, coconut milk, and vanilla. Beat the mixture on medium speed for 30 seconds or until combined.
Next, add half the flour mixture and beat on low speed until combined. Slowly add the rest of the flour and mix until incorporated. Scrape down the sides of the bowl and mix in any dry flour with a spatula.
Carefully fold the apples into the batter with a silione spatula.
Transfer the batter to the greased bundt pan and smooth the top.
Pop the pan in the oven and bake until the cake is golden brown and a toothpick inserted in the center comes out clean, about 55 to 70 minutes.
Cool the cake in the pan on a cooling rack for 15 minutes. Invert the cake on a wire rack and cool completely, about two hours. Slice and enjoy!