Preheat the oven to 180 C and prepare a round baking tray, preferably with a detachable bottom, 20 cm in diameter.
We place a piece of parchment paper on the bottom of the tray, and grease the edges with a little butter and dust them with flour.
In a bowl, mix the cubed butter with the sugar until creamy.
We gradually incorporate the eggs, one by one, and mix until they are well combined.
We add the vanilla, kefir, and mix.
We integrate with a spatula the flour, cinnamon, baking powder, and baking soda, slowly, without mixing too much.
Once the composition has homogenized, pour half into the prepared tray. Arrange the apple slices (leaving a few slices, about one apple, to place on top), then pour the rest of the composition and level everything.
On top, we place the remaining slices, add almond flakes, and bake the cake in the preheated oven for 45-55 minutes.
Once the cake is ready, let it cool slightly and serve.
Enjoy!
