Preheat an oven to 180c (350f) and prepare a 9x9 inch cake pan with parchment paper.
Wash and dry the apples with a towel and in a box grater, on the smaller holes (to get finely grated apples) great the apples with the peel on.
Into a large mixing bowl, add the grated apples, sour cream, oil, brown sugar, sugar, vanilla extract, applesauce, cinnamon, nutmeg, ginger, eggs, and salt, and mix with a whisk until well combined.
Add the flour, and baking soda and mix with a whisk until there are no lump of flour visible.
Pour the cake batter into a prepared 9 by 9 inch pan with parchment paper and smooth it out using a rubber spatula. Evenly sprinkle ¼ cup of sugar on top to create a crunchy and sweet layer of caramelized sugar on top.
Bake in a 180c (350f) preheated oven for 40-45 minutes (depending on your oven) or until a toothpick comes out clean with a few moist crumbs but not wet batter.
Allow the cake to reach room temperature for at least 1 hour.
Make the cream cheese frosting
In a large mixing bowl add the heavy cream, powdered sugar, cinnamon, and vanilla extract, and mix with an electric hand mixer until stiff peaks form.
Add the cream cheese and mix until smooth and creamy.
Top the cooled cake with the whipped cream cheese frosting and make swirls using an offset spatula. Sprinkle cinnamon on top and serve!
Notes
Measure your flour correctly! When measuring your flour, avoid scooping it with a measuring cup. Instead, stir the flour with a spoon to create as many air pockets as possible, and spoon it into your measuring cup. Finally, level it with a back of a knife.
Grate the apples finely. Use a box grater to shred the apples into small pieces. This ensures even distribution throughout the cake and helps maintain moisture.
Don’t overmix the batter, you don’t want to develop the gluten in the flour. This step ensures you have a moist cake and not a dense and dry cake.
When baking, Granny Smith apples are a great choice because they're tart and firm, which helps them keep their shape and add a nice flavor to baked goods.
Line your baking pan with parchment paper! This step helps the cake to bake evenly, and it makes sure that your loaf cake will release easily from the pan.
Scrape down the sides and the bottom of the bowl frequently to ensure that you have a homogeneous mixture that has unmixed parts of the mixture.
Don't overbake. Check the cake 5-10 minutes before the recommended baking time. Insert a toothpick into the center; if it comes out with a few moist crumbs, the cake is done.
Cool completely before frosting. Allow the cake to cool in the pan for 10 minutes, then transfer to a wire rack. Ensure it's completely cool before applying the cream cheese frosting to prevent melting.