Preheat the oven to 180°C (350°F) and line a 22cm (9 inches) round cake tin with vegetable oil and parchment paper. Line the sides and bottom of the cake tin.
Peel and slice the apples into fine slices of about 5mm (about ¼ inch) in thickness. Add the apple slices and lemon juice to a large bowl and stir to combine.
Add the butter and sugar to a bowl of a stand mixer fitted with a paddle attachment. Beat until creamed, about 3 – 5 minutes.
With the mixer at medium speed, add the eggs to the creamed butter and sugar mixture one at a time, be sure to scrape down the sides of the bowl with a rubber spatula between each addition. Add the vanilla and beat again.
Sift together the flour, baking powder, and salt into a large mixing bowl.
Add the wet and dry ingredients to the cake batter by alternating between the two. Starting with the flour mixture and ending with the sour cream.
Add the sliced apples to the cake batter and mix through using a rubber spatula.
Pour the cake batter into the prepared pan and smooth over the top with an offset palette knife.
Combine the ground cinnamon and granulated sugar in a small bowl then sprinkle this evenly over the top of the cake.
Bake the cake in a preheated oven for 45 minutes or until golden brown and a cake tester inserted into the center of the cake comes out clean.
Allow the cake to cool in its tin for 10 minutes before turning it onto a wire rack to cool completely. Once cool, transfer it onto a serving plate and dust it with icing sugar. Serve and enjoy.