Preparation:

For the cake

In a mixer’s bowl, add the eggs, the sugar, the vanilla paste and mix with the whisk attachment over medium to high speed, until they turn white and completely fluffy.
Lower the mixer’s speed and gradually add OLYMPOS Milk of Life. Next, add OLYMPOS strained yogurt 5%, the melted OLYMPOS cow butter and resume mixing, until all ingredients are entirely incorporated.
Stop the mixer and remove the bowl. In another bowl, mix the flour, the baking powder, cinnamon and salt and sift directly into the mixer’s bowl. Add the orange zest and stir with a spatula, until you get a homogenous mixture.
Place some parchment paper at the bottom of the cake pan, spread the butter evenly over the whole surface of the parchment paper, place one layer of apples on top and pour the cake batter. Spread the cake batter over the cake pan and bake in pre-heat oven at 170°C for approximately 45 minutes, check baking by inserting a small knife within the cake and remove it from the oven.
Let the cake come at room temperature and turn it out onto a serving platter.

Cut in slices and serve.

For the butter mixture

In a bain-marie add the butter and the sugar and mix occasionally, until the butter melts completely. Remove the bowl from the bain-marie, add cinnamon and stir with the whisk attachment, until it is entirely homogenized. Place the bowl in the refrigerator and stir every ten minutes with the whisk, until the mixture thickens and becomes homogenous, for approximately 45 minutes.